PELARGONİK ASİT = NONANOİK ASİT = NONİLİK ASİT = PELARJİK ASİT
EC / Liste no .: 203-931-2
CAS no .: 112-05-0
Mol. formül: C9H18O2
Nonanoik asit (sıklıkla pelargonik asit olarak anılır), genellikle orta zincirli yağ asitleri (C8 ila C12) olarak adlandırılan, doymuş yağ asitlerinin kimyasal sınıfına ait, dokuz karbon zinciri uzunluğuna sahip, doğal olarak oluşan bir karboksilik asittir.
Pelargonik asit, hafif kokulu, berrak, renksiz bir sıvıdır.
Pelargonik asit (Nonanoik asit) sulu çözeltilerde çözünür, ancak kolayca ester oluşturabilir ve sulu bir çözelti içinde pelargonat anyon (CH3 (CH2) 7COO-) ve hidronyum katyonu (H3O +) içinde kısmen ayrışabilir. Nonanoik asidin moleküler ağırlığı (158.24 g / mol) ve oktanol-su bölme katsayısı (3.4 logPow), dermal penetrasyonun mümkün olduğunu göstermektedir.
Pelargonik asit, tarım ve veterinerlik kimyasal ürünlerinde bir herbisit olarak kullanılır ve terapötik ürünlerde veya kokularda başka kullanımlara sahip olabilir.
ANAHTAR KELİMELER:
203-931-2, 112-05-0, PELARGONİK ASİT, NONANOİK ASİT, NONİLİK ASİT, PELARJİK ASİT, Yağ asitleri C8-10, Nonansaeure, Pelargonsaeure, pergonik
Nonanoik asit, orta zincirli doymuş bir yağ asididir.
Nonanoik asit, bitki patojenik mantarları M. roreri ve C. perniciosa'da konsantrasyona bağlı olarak misel büyümesini ve spor çimlenmesini inhibe eder. Yengeç otu dahil çeşitli türlere karşı herbisidal aktiviteye sahiptir.
Nonanoik asit, zeytin değirmeni atık sularında serbest yağ asitlerinin miktarının belirlenmesi için bir iç standart olarak kullanılmıştır.
Nonanoik asit içeren formülasyonlar, iç ve dış mekan ot kontrolünde ve kozmetikte temizleyici ve emülsifiye edici ajan olarak kullanılmıştır.
Nonanoik asit olarak da adlandırılan pelargonik asit, CH3 (CH2) 7CO2H yapısal formülüne sahip organik bir bileşiktir.
Pelargonik asit, dokuz karbonlu bir yağ asididir. Nonanoik asit, hoş olmayan, ekşimiş bir kokuya sahip renksiz yağlı bir sıvıdır.
Pelargonik asit suda neredeyse çözünmez, ancak organik çözücülerde çok çözünür.
Pelargonik asidin esterleri ve tuzları, pelargonatlar veya nonanoatlar olarak adlandırılır.
Pelargonik asit, herbisit formülasyonlarında ve plastikleştiriciler, reçineler, yağlayıcılar ve cilaların hazırlanmasında kullanılır.
Pelargonik asit veya Nonanoik Asit, doğal olarak pelargonium yağının esterleri olarak oluşan bir C9 düz zincirli doymuş yağ asididir.
Pelargonik asit, antifungal özelliklere sahiptir ve ayrıca bir herbisit olarak ve ayrıca plastikleştirici ve verniklerin hazırlanmasında kullanılır.
Nonanoik Asit, dokuz karbon atomlu, doğal olarak oluşan doymuş bir yağ asididir. Nonanoik asidin amonyum tuzu formu bir herbisit olarak kullanılır.
Nonanoik Asit, bitkinin mumsu kütikülünü soyarak hücre bozulmasına, hücre sızıntısına ve kuruma yoluyla ölüme neden olarak çalışır.
Nonanoik asit, doğal olarak pelargonium yağının esterleri olarak oluşan C9 düz zincirli doymuş yağ asididir.
Nonanoik asit, antifungal özelliklere sahiptir ve ayrıca bir herbisit olarak ve ayrıca plastikleştirici ve cilaların hazırlanmasında kullanılır.
Nonanoik asit, bir antifeedant, bir bitki metaboliti, bir Daphnia magna metaboliti ve bir algal metaboliti olarak rol oynar.
Nonanoik asit, düz zincirli doymuş bir yağ asidi ve orta zincirli bir yağ asididir. Nonanoatın eşlenik asididir. Nonanoik asit, bir nonanın hidritinden türetilir.
Nonanoik asit (Pelargonik asit, Nonoik asit), hem bitkisel hem de hayvansal yağlarda bulunan doğal olarak oluşan bir yağ asididir.
Nonanoik asit (NNA), orta zincirli bir yağ asididir ve dokuz karbon zinciri uzunluğuna sahip doğal olarak oluşan bir karboksilik asittir.
Nonanoik asit, tarımsal ve veterinerlik (AgVet) kimyasal ürünlerinde bir herbisit olarak kullanılır ve terapötik ürünlerde veya kokularda başka kullanımlara sahip olabilir.
Nonanoik asit, hem diğer aktif maddelerle (özellikle glifosat) hem de bağımsız bir aktif bileşen olarak bir herbisit olarak bir dizi tarımsal kimyasalda kullanılmıştır.
Yüksek konsantrasyonlarda Nonanoik asit içeren ticari ürünler mevcuttur. Nonanoik asit, hem kullanıma hazır formülasyonlarda hem de kullanımdan önce seyreltme gerektiren konsantre formülasyonlarda, ev bahçesinde kullanım için ürünler olarak mevcuttur.
Nonanoik asit veya pelargon olarak da bilinen pelargonik asit, orta zincirli yağ asitleri olarak bilinen organik bileşikler sınıfına aittir.
Bunlar alifatik kuyruğu 4 ila 12 karbon atomu içeren yağ asitleridir.
Pelargonik asit, hoş olmayan, ekşimiş bir kokuya sahip yağlı bir sıvıdır.
Çok hidrofobik bir moleküldür, suda pratik olarak çözünmez, ancak organik çözücüler içinde çok çözünür.
Yağ asidinin biyosentezi, asetat yolu ile gerçekleşir ve süreç, Yağ Asidi Sentaz (FAS) enzimleri tarafından katalize edilir.
Yapısal olarak, FAS farklı organizmalar arasında önemli ölçüde farklılık gösterir, ancak esasen hepsi aynı mekanizmaları kullanarak aynı görevi yerine getirir.
Nonanoik asit ayrıca plastikleştirici ve cilaların hazırlanmasında da kullanılır. Metil nonanoat gibi sentetik nonanoik asit esterleri tatlandırıcı olarak kullanılır.
Türev 4-nonanoilmorfolin, bazı biber spreylerinde bulunan bir bileşendir. Nonanoik asidin amonyum tuzu olan amonyum nonanoat bir herbisittir.
Çimlerdeki yabani otları kontrol etmek için yaygın olarak seçici olmayan bir herbisit olan glifosat ile birlikte kullanılır.
Pelargonik asit, berrak ila sarımsı yağlı bir sıvıdır. Suda çözünmez ancak eter, alkol ve organik çözücülerde çözünür.
Çoğu doğal yağ asidi molekülü, ester birimleri tarafından birbirine bağlanması nedeniyle çift sayıda karbon zincirine sahiptir.
Tek sayılı karbon zinciri yağ asitlerinin benzer bileşikleri sentetik olarak desteklenir.
Pelargonik asit, C-9 tek sayılı karbon zinciri yağ asidi, nispeten yüksek maliyetli yağ asididir.
Pelargonik asit, alken bağlarını ayırmak için ozon kullanan ozonoliz ile hazırlanabilir.
Ticarette ozonoliz örneği, azelaik asit ve pelargonik asit gibi tek karbon sayılı karboksilik asitlerin ve formik asit ve oksalik asit gibi basit karboksilik asitlerin üretimidir.
Pelargonik asit, plastikleştirici ve yağlama yağları olarak kullanılmak üzere alkollü esterleri oluşturur.
Doymuş pelargonik asit oksitlenmeyeceğinden renk bozulmasını önlemek ve yaşlanmaya karşı esnekliği ve direnci korumak için alkid reçinelerin modifiye edilmesinde kullanılır.
Stabilizatör olarak kullanılan metalik sabunlar (baryum ve kadmiyum) ve diğer inorganik tuzlar.
Aynı zamanda sentetik tatlar, kozmetikler, farmasötikler ve korozyon inhibitörleri için kimyasal bir ara ürün olarak kullanılır.
C8 - C12 düz ve doymuş zincirli yağ asitlerinin, geniş yaprağın veya yabani otun mumsu kütikülünü çıkararak doku ölümüne neden olduğu bilinmektedir. T
çevre dostu ve çabuk etkili herbisitlerin etken maddesi olarak kullanılmaktadır. Pelargonik asit en güçlüsüdür.
Nonanoik asit, nöbetleri tedavi etmek için kullanılabilir (PMID 23177536).
Diğer isimler: n-Nonanoik asit; n-Nonoik asit; n-Nonilik asit; Nonoik asit; Nonilik asit; Pelargic asit; Pelargonik asit; 1-Oktankarboksilik asit; Cirrasol 185a; Emfac 1202; Hexacid C-9; Pelargon; Emery 1203; 1-Nonanoik asit; NSC 62787; n-Pelargonik asit; Zımpara 1202 (Tuz / Karışım)
IUPAC Adı: nonanoik asit
Eş anlamlı:
1-nonanoik asit
1-oktankarboksilik asit
CH3‒ [CH2] 7 ‒ COOH IUPAC
n-nonanoik asit
n-nonanoik asit
Nonanoat
Nonanoik asit
Nonansäure Deutsch
nonoik asit
nonilik asit
pelarjik asit
sardunya
Pelargonik asit
Pelargonsäure Deutsch
pergonik asit
nonanoik asit, ana hidrit nonana sahiptir
nonanoik asidin rolü Daphnia magna metabolitidir
nonanoik asit algal metabolite rol oynar
nonanoik asidin rolü antifeedant
nonanoik asit, bitki metaboliti rolüne sahiptir
nonanoik asit, orta zincirli bir yağ asididir
nonanoik asit, düz zincirli doymuş bir yağ asididir
nonanoik asit, nonanoatın eşlenik asididir
EŞ ANLAMLI :
ANOİK ASİT
Pelargonik asit
112-05-0
n-Nonanoik asit
Nonoik asit
Nonilik asit
Pelarjik asit
n-Nonilik asit
n-Nonoik asit
1-Oktankarboksilik asit
Pelargon
Cirrasol 185A
Hekzasit C-9
Emfac 1202
1-nonanoik asit
Yağ asitleri, C6-12
Yağ asitleri, C8-10
Cevapsız
Pelargonsaeure
pergonik asit
MFCD00004433
nonoate
NSC 62787
UNII-97SEH7577T
68937-75-7
CH3- [CH2] 7-COOH
CHEBI: 29019
97SEH7577T
pergonat
n-nonanoat
1-nonanoat
C9: 0
oktan-1 karboksilik asit
1-oktankarboksilat
n-Nonanoik asit,% 97
DSSTox_CID_1641
DSSTox_RID_76255
DSSTox_GSID_21641
Pelargon [Rusça]
1-Oktankarboksilik asit
CAS-112-05-0
2784 sayılı FEMA
HSDB 5554
EINECS 203-931-2
EPA Pestisit Kimyasal Kodu 217500
BRN 1752351
n-Pelargonat
AI3-04164
n-Nonylate
Perlargonik asit
n-Nonoate
n-pelargonik asit
KNA
EINECS 273-086-2
Nonanoik Asit Anyonu
Asit C9
Kaprilik-Kaprik Asit
Nonanoik asit,% 96
3sz1
Emery's L-114
Pelargonik Asit 1202
Zımpara 1202
Zımpara 1203
oktan-1-karboksilik asit
Hazırlık, oluşum ve kullanımlar
Pelargonik asit, pelargonium yağında doğal olarak esterler olarak bulunur.
Azelaik asit ile birlikte endüstriyel olarak oleik asidin ozonoliziyle üretilir.
H17C8CH = CHC7H14CO2H + 4O → HO2CC7H14CO2H + H17C8CO2H
Tatlandırıcı olarak metil pelargonat gibi pelargonik asidin sentetik esterleri kullanılır.
Pelargonik asit ayrıca plastikleştirici ve verniklerin hazırlanmasında da kullanılır.
Türev 4-nonanoilmorfolin, bazı biber spreylerinde bulunan bir bileşendir.
Pelargonik asidin amonyum tuzu, amonyum pelargonat, bir herbisittir.
Çimlerdeki yabani otların kontrolünde hızlı bir yanma etkisi için yaygın olarak seçici olmayan bir herbisit olan glifosat ile birlikte kullanılır.
Farmakolojik etkiler
Pelargonik asit, nöbetlerin tedavisinde valproik asitten daha güçlü olabilir.
Ayrıca, valproik asidin aksine pelargonik asit, HDAC inhibisyonu üzerinde hiçbir etki göstermedi, bu da HDAC inhibisyonu ile ilişkili teratojenisite göstermesinin olası olmadığını düşündürdü.
IUPAC adı: Nonanoik asit
Diğer isimler: Nonoik asit; Nonilik asit;
1-Oktankarboksilik asit;
C9: 0 (Lipid sayıları)
Tanımlayıcılar
CAS Numarası: 112-05-0
EC Numarası: 203-931-2
Özellikleri
Kimyasal formül: C9H18O2
Molar kütle: 158.241 g · mol − 1
Görünüm: Berrak ila sarımsı yağlı sıvı
Yoğunluk: 0,900 g / cm3
Erime noktası: 12,5 ° C (54,5 ° F; 285,6 K)
Kaynama noktası: 254 ° C (489 ° F; 527 K)
Kritik nokta (T, P): 439 ° C (712 K), 2,35 MPa
Suda çözünürlük: 0.3 g / L
Asitlik (pKa): 4.96
2,06 ila 2,63 K'da 1,055 (-271,09 ila -270,52 ° C; -455,96 ila -454,94 ° F)
1,53 -191 ° C'de (-311,8 ° F; 82,1 K)
Kırılma indisi (nD): 1.4322
Tehlikeler
Ana tehlikeler: Aşındırıcı (C)
R cümleleri (eski): R34
S-ibareleri (modası geçmiş): (S1 / 2) S26 S28 S36 / 37/39 S45
Parlama noktası: 114 ° C (237 ° F; 387 K)
Kendiliğinden tutuşma sıcaklığı: 405 ° C
Kategoriler: Alkanoik asitler
Herbisitler
Pelargonik Asit
Pelargonik asit, ıtırlarda doğal olarak bulunur ve istenmeyen bitkilerin tedavisinde yaygın olarak kullanılan oldukça etkili bir yağ asididir.
Pelargonic Acid nasıl çalışır?
Pelargonik asit, yabani ot yapraklarının hücre duvarlarını tahrip eder.
Bu, hücrelerin yapılarını kaybetmesine ve kısa bir süre içinde kurumasına neden olur, normal şartlar altında bu, tedaviden sonraki 1 gün içinde görülecektir.
Bu hareketten sadece bitkinin yeşil kısımları etkilenir, hücrelerin çok stabil olması ve aktif içeriğin yüzeye nüfuz etme yolu olmadığı için bitkinin odunsu kabuğu etkilenmez.
Bu nedenle ürün, tüm alanı tahrip etme korkusu olmadan çitlerin, ağaçların ve çalıların altında kullanılabilir.
Kullanımlar
Pelargonik asit, birçok bitki ve hayvanda doğal olarak bulunur.
Pelargonik asit, yabani otların büyümesini kontrol etmek ve elma ve armut ağaçları için çiçek inceltici olarak kullanılır.
Pelargonik asit ayrıca bir gıda katkı maddesi olarak kullanılır; ticari olarak meyve ve sebzeleri soymak için kullanılan solüsyonlarda bir bileşen olarak.
Pelargonik asit birçok bitkide bulunur.
Pelargonik asit, hem içeride hem de dışarıda yabancı otların büyümesini önlemek için herbisit olarak, elma ve armut ağaçlarında çiçek inceltici olarak kullanılır.
ABD Gıda ve İlaç Dairesi (FDA) bu maddenin gıdalarda kullanılmasını onaylamıştır.
Pelargonik asit içeren pestisit ürünleri etiket talimatlarına göre kullanıldığında insanlar veya çevre için herhangi bir risk beklenmemektedir.
I. Etkin Bileşenin Tanımı Pelargonik asit, hemen hemen tüm hayvan ve bitki türlerinde bulunan kimyasal bir maddedir.
Dokuz karbon atomu içerdiği için nonanoik asit olarak da adlandırılır.
Yediğimiz yaygın yiyeceklerin çoğunda düşük seviyelerde bulunur.
Çevrede kolaylıkla parçalanır.
II. Kullanım Alanları, Hedef Zararlılar ve Uygulama Yöntemleri Pelargonik asidin bitkilerle ilgili iki farklı kullanımı vardır: yabani ot öldürücü ve çiçek inceltici.
[Not: Madde dezenfektan olarak kullanılabilir, bu Bilgi Formunda belirtilmeyen bir kullanım.]
o Yabancı ot öldürücü Yetiştiriciler, yabani otlara karşı korumak için gıda mahsullerine ve diğer mahsullere pelargonik asit püskürtür.
Gıda mahsulleri için, pelargonik asidin ekim zamanından hasattan 24 saat öncesine kadar uygulanmasına izin verilir.
Hasat öncesi kısıtlama, yiyecek üzerinde çok az veya hiç kalıntı kalmamasını sağlar.
Kimyasal ayrıca okullar, golf sahaları, yürüyüş yolları, seralar ve çeşitli kapalı alanlar gibi sitelerdeki yabani otları da kontrol eder.
o Çiçek inceltici Yetiştiriciler, elma ve diğer meyve ağaçlarının kalitesini ve verimini artıran bir prosedür olan ince çiçekler için pelargonik asit kullanırlar.
Çiçeklerin seyreltilmesi, ağaçların iki yılda bir yerine her yıl meyve vermesini sağlar.
III. İnsan Sağlığına Yönelik Risklerin Değerlendirilmesi Pelargonik asit, gıda bitkileri de dahil olmak üzere birçok bitkide doğal olarak bulunur, bu nedenle çoğu insan düzenli olarak bu kimyasalın küçük miktarlarına maruz kalır.
Pelargonik asidin gıda mahsullerinde herbisit veya çiçek inceltici olarak kullanımının insan maruziyetini veya riskini artırması beklenmemektedir.
Ayrıca testler, pelargonik asidi küçük miktarlarda yutmanın veya solumanın bilinen hiçbir toksik etkisinin olmadığını göstermektedir.
Pelargonik asit cildi ve gözü tahriş edicidir ve ürün etiketleri, ürünlerin gözlerine veya cildine bulaşmasını önlemek için kullanıcıların uyması gereken önlemleri açıklar.
PELARGONİK ASİTİN BİR OT YÖNETİM ARACI OLARAK KULLANIMI
Steven Savage ve Paul Zomer Mycogen Corporation, San Diego, California 1995 yılında, Mycogen Corporation,% 60 aktif bileşen, pelargonik asit içeren yanmış bir herbisit olan Scythe®'yi piyasaya sürdü.
Pelargonik asit, doğal olarak oluşan, doymuş, dokuz karbonlu bir yağ asididir (C9: 0).
Pelargonik asit, doğada keçi sütü, elma ve üzüm gibi ürünlerde yaygın olarak bulunur.
Ticari olarak sığır donyağından oleik asidin (C18: 1) ozonoliziyle üretilir.
Pelargonik asit çok düşük memeli toksisitesine sahiptir (oral, soluma), mutajenik, teratojenik veya hassaslaştırıcı değildir.
Göz ve cilt tahrişine neden olabilir ve bu nedenle formüle edilmiş ürün bir UYARI sinyal kelimesi (Kategori II) taşır.
İyi huylu bir çevre profiline sahiptir. Bir herbisit olarak, pelargonik asit, yeşil dokuların son derece hızlı ve seçici olmayan yanmasına neden olur.
Öldürme oranı sıcaklığa bağlıdır, ancak en soğuk koşullar dışında, muamele edilen bitkiler 15-60 dakika içinde hasar göstermeye başlar ve uygulamadan sonra 1-3 saat içinde çökmeye başlar.
Pelargonik asit sistemik değildir ve odunsu dokulardan geçmez.
Ayrıca yosunlara ve diğer kriptograflara karşı da etkindir. Pelargonik asidin toprak aktivitesi yoktur.
Yakılan herbisitlerin çoğunda olduğu gibi, pelargonik asit, korumalı tomurcuklardan veya bazal meristemlerden yeniden büyümeyi engellemez.
Birçok yıllık otsu yabani ot tamamen öldürülürken, daha büyük yabani otlar, otlar ve odunsu bitkiler yeniden büyüyebilir.
Pelargonik asidin hızlı yanma aktivitesinin birçok pratik uygulaması vardır.
Nokta ayıklama, kenar düzeltme, astarlama, çim yenileme, kimyasal budama ve emiş için kullanılabilir.
Özellikle, kapta yetişen odunsu süs bitkilerinde, sera tezgahlarının altında ve sistemik herbisitlerin istenmeyen hasara neden olabileceği diğer yerlerde yıllık yabani otları öldürmek için yönlendirilmiş bir sprey olarak kullanışlıdır.
Pelargonik asit spreyi istenen bazı bitkilerle temas ederse, hasar kesinlikle gerçekten püskürtülen yapraklarla sınırlıdır.
Pelargonik asit, daha düşük galonajlarda aktivite azaldığından, toplam sprey hacminin en az 75 galon / akrelik alanına uygulanmalıdır.
P31 NMR çalışmalarından elde edilen kanıtlar, pelargonik asidin etki tarzının hücre zarlarına doğrudan hasara dayanmadığını göstermektedir.
Pelargonik asit, kütikül ve hücre zarları boyunca hareket eder ve bitki hücrelerinin iç pH'ını düşürür.
Sonraki birkaç dakika içinde hücresel ATP ve Glikoz-6-fosfat havuzları azalır.
Ancak daha sonra, sonunda hücre sızıntısına, dokunun çökmesine ve kurumasına yol açan membran disfonksiyonunun kanıtı vardır.
Bu hücresel olaylar zinciri, pelargonik asidin glifosat gibi belirli sistemik herbisitlerin aktivitesini sinerji oluşturmasına izin veriyor gibi görünmektedir.
Genel olarak, yanmış herbisitler, sistemik herbisitlerin aktivitesine antagonisttir, ancak bir tank karışımında pelargonik asidin, translokasyona müdahale etmeden daha büyük ve daha hızlı glifosat alımına izin verdiği gösterilmiştir.
Bu tür bir sinerji, glifosat için yardımcı maddeler veya formülasyon bileşenleri olarak kullanılan çeşitli yüzey aktif maddelerle görülen artıştan tamamen farklıdır.
Bir tank karışımının yüksek hacimli uygulamalarının kullanılmasıyla, pelargonik asidin hızlı öldürülmesi ile glifosatın sistemik etkisinin birleştirilmesi mümkündür.
Düşük uygulama hacimlerinde (örn. 20-30 GPA), pelargonik asit glifosat alımını hala arttırır ve genel performansını iyileştirir, ancak işlenmiş yapraklarda hemen yanma olmaz.
Scythe herbisit, 1995'te mahsul dışı kullanım için tescil edildi ve 1996'da mahsul kaydı bekleniyor.
Pelargonik asidin bu ticari formülasyonu, hem temaslı, seçici olmayan bir ajan olarak hem de glifosat gibi sistemik herbisitlerle bir tank karıştırma ortağı olarak çok çeşitli yabani ot kontrol uygulamalarına sahiptir.
Farklı Pelargonik Asit Ürünlerinin ve Uçucu Yağların Bazı Önemli Yabancı Ot Türlerine Karşı Herbisidal Potansiyeli
Ilias Travlos 1, *, Eleni Rapti 1, Ioannis Gazoulis 1, Panagiotis Kanatas 2, Alexandros Tataridas 1, Ioanna Kakabouki 1 ve Panayiota Papastylianou 1 1
Agronomi Laboratuvarı, Mahsul Bilimi Bölümü, Atina Ziraat Üniversitesi, 75 Iera Odos str., 118 55 Atina, Yunanistan;
30 Ekim 2020 tarihinde yayınlandı.
Özet: Yeterli düzeyde yabancı ot kontrolü sağlayan doğal herbisitlerin geliştirilmesine ilişkin olarak çiftçiler ve araştırmacılar arasında giderek artan bir ilgi vardır.
Bu çalışmanın amacı, dört farklı pelargonik asit ürünü, üç uçucu yağ ve iki doğal ürün karışımının L. rigidum Gaud., A. sterilis L. ve G. aparine L.'ye karşı etkinliğini karşılaştırmaktır. tedaviden 7 gün sonra PA3 işleminin (pelargonik asit% 3.102 w / v + maleik hidrazid% 0.459 w / v) L. rigidum ve A. sterilis'e karşı en az etkili tedavi olduğu fark edildi. Limon otu yağı ve pelargonik asit karışımı, kontrole kıyasla L. rigidum için% 77 daha düşük kuru ağırlık ile sonuçlandı. Manuka yağı durumunda kontrol ile karşılaştırıldığında biyokütle azalması% 90 seviyesine ulaştı ve manuka yağı ile pelargonik asit karışımının etkinliği benzerdi.
Steril yulaf için yabani ot biyokütlesi, limon otu yağı, çam yağı, PA1 (pelargonik asit% 18.67 + maleik hidrazit% 3) ve PA4 (pelargonik asit% 18.67) tedavileri için kontrolün% 31 ila% 33'ü arasında kaydedildi. Ek olarak, manuka yağı ve pelargonik asit karışımı yabani ot biyokütlesini kontrole kıyasla% 96 oranında düşürdü.
Geniş yapraklı türler G. aparine ile ilgili olarak, PA4 ve PA1 muameleleri, muamele edilmemiş bitkiler için kaydedilen karşılık gelen değere kıyasla% 96-97'lik bir kuru ağırlık azalması sağlamıştır.
PA2 (pelargonik asit% 50 w / v) muamelesi ve manuka yağı ve pelargonik asit karışımı yarma bitkilerini tamamen ortadan kaldırdı.
Tür düzeyinde yabancı ot kuru ağırlığı için yapılan gözlemler, her tür için kaydedilen bitki boyu değerleri ile ilgili yapılan gözlemlere benzer olmuştur.
Farklı toprak ve iklim koşulları altında yabancı ot yönetimi stratejilerinde doğal herbisitlerin yanı sıra doğal herbisitlerin karışımlarının kullanımını optimize etmek ve daha doğal maddeleri incelemek için daha fazla araştırmaya ihtiyaç vardır. Anahtar Kelimeler: biyoherbisid; pelargonik asit; manuka yağı; limon otu yağı; çam yağı; ot otları; geniş yapraklı yabani otlar 1.
Giriş Yabani otlar, doğal kaynaklar için mahsulle rekabet ederek, mahsul zararlılarını barındırarak, mahsul verimini ve kalitesini düşürerek ve ardından işleme maliyetini artırarak mahsul üretimini dolaylı olarak etkiledikleri için tarımsal üretime yönelik en büyük tehditlerden biri olarak kabul edilir [1 ]. Kimyasal kontrol, yabancı ot yönetimi için en yaygın kontrol uygulaması olmaya devam etmektedir. Ne yazık ki, herbisitlere olan bu aşırı bağımlılık, hedeflenmeyen bitki örtüsü ve mahsullerin olası yaralanması, suda ve toprakta herbisit kalıntılarının varlığı ve insan sağlığı ve güvenliği endişeleri gibi ciddi sorunlara yol açmıştır [2-5].
Sentetik herbisit kullanımıyla ilişkili bir diğer önemli sorun ise Agronomy 2020, 10, 1687; doi: 10.3390 / agronomy10111687 www.mdpi.com/journal/agronomy Agronomy 2020, 10, 1687 2/13 Amaranthus, Conyza, Echinochloa ve Lolium spp. çok çeşitli herbisit etki alanlarına karşı hızla direnç geliştirme yetenekleriyle ünlüdür.
Organik asitlere veya uçucu yağlara dayalı doğal herbisitlerin geliştirilmesi bu olumsuz etkileri azaltabilir.
Sentetik herbisitlere kıyasla daha az kalıcıdırlar, daha çevre dostudurlar ve ayrıca herbisite dayanıklı yabani ot biyotiplerinin gelişimini önleyebilecek farklı etki modlarına sahiptirler [7,8]. Bitki dokularından elde edilen organik asitler, uçucu yağlar, ham botanik ürünler ve diğer doğal maddeler, hem organik hem de sürdürülebilir tarım sistemlerinde yabancı ot yönetimi açısından biyo-herbisit olarak kullanılabilir [9].
Bu tür doğal maddeler, ticari ölçekte kullanımları için ilgili toksikolojik verilerin eksikliğinden dolayı doğal ürünlerin tescil işlemlerine ilişkin şüpheler olduğundan, Avrupa Komisyonu üyeleri arasında birçok rakiple karşı karşıyadır [10]. Bu endişeler mevcut olsa da, çoğu uçucu yağın ve ana bileşenlerinin mutlaka genotoksik veya insan sağlığına zararlı olmadığına dair kanıtlar vardır [11]. Bu tür doğal herbisitler, ticari sentetik herbisitlere kıyasla çevre ve insan sağlığı için bazen daha az tehlikelidir.
Pelargonik asit durumunda, kuşlar, balıklar ve bal arıları gibi hedef olmayan organizmalar üzerindeki toksisite testleri, çok az toksisite ortaya koymuştur veya hiç göstermemiştir.
Kimyasal hem kara hem de su ortamlarında hızla ayrışır, bu nedenle birikmez.
Hedef dışı bitkilere sürüklenmeyi ve olası zararı en aza indirmek için, kullanıcıların rüzgarlı günlerden kaçınmak ve büyük sprey damlacıkları kullanmak gibi önlemler almaları gerekmektedir.
Bununla birlikte, ürün etiketleri, asit cildi ve gözü tahriş edici olduğundan ürünlerin gözlerine veya cildine bulaşmasını önlemek için kullanıcıların uyması gereken önlemleri tanımlar [13].
Pelargonik asit (PA) (CH3 (CH2) 7CO2H, n-nonanoik asit) Pelargonium spp. Ve çeşitli bitki türlerinin dokularından elde edilebilir [14-16]. Pelargonik asit, tuzları ile birlikte ve emülgatörlerle formüle edilmiş olup, dünya çapında gerek bahçe gerekse profesyonel kullanım için uygun seçici olmayan bir herbisit olarak yabancı ot yönetimi açısından kullanılmaktadır [8,14].
Hücre zarlarına saldıran temaslı yanma herbisitleri olarak uygulanırlar ve bunun sonucunda hücre sızıntısına neden olur ve ardından zar açil lipitleri parçalanır.
Pelargonik asit uygulamasına bağlı fitotoksik etkiler, püskürtmeden çok kısa bir süre sonra görülür ve semptomlar, bitkiler ve hücreleri için hızla oksitlenmeye başlayan fitotoksisiteyi içerir ve bitkilerin toprak üstü kısımlarında nekrotik lezyonlar görülür [18 ].
Pelargonik asidin bir biyoherbisid olarak potansiyel kullanımı, soya fasulyesi gibi önemli mahsullerde diğer çevre dostu yabancı ot yönetimi stratejileriyle etkili bir şekilde entegre edilebilen çekici bir kimyasal olmayan yabancı ot kontrol seçeneği sunar [19]. Birkaç ticari pelargonik asit bazlı doğal herbisit, aynı zamanda, piyasaya çıktığından beri bir herbisit olarak da kullanılan sistemik bir bitki büyüme düzenleyicisi olan maleik hidrazidi (1,2-dihidro-3,6-piridazindion) içerir [20].
Maleik hidrazid (1, 2-dihidropiridazin-3, 6-dion) sentezlenen ve ilk kez 1949'da ABD'ye sunulan, kristal yapısı ve pirimidin baz urasile yapısal benzerliği olan hormon benzeri bir madde [20-22].
Yapraklara uygulandıktan sonra, maleik hidrazid, hem floem hem de ksilemde hareketlilik ile meristematik dokularda yer değiştirir.
Etki şekli net olmasa da, soğan ve havuç gibi sebze mahsullerinde filizin bastırılmasında ve sentetik herbisitlerin sınırlı olduğu sorunlu parazitik yabancı ot türlerinin kontrolünde etkili bir şekilde kullanılabilir [24-26]. Çeşitli aromatik, biyokütle, istilacı veya gıda mahsul bitkilerinden elde edilen uçucu yağların da doğal seçici olmayan herbisitler olarak potansiyele sahip olduğu bilinmektedir [9,27-29].
Benzer şekilde, pelargonik asit durumunda, yabani otların yaprakları uygulamadan çok kısa bir süre sonra yanar, bu da genç bitkilere karşı yaşlı bitkilere göre daha etkilidir [30].
Manuka yağı, Leptospermum scoparium J. R. Forst. ve G. Forst. organik standartlar açısından kabul edilebilir bir ürün olarak kabul edilmektedir [9].
Bu uçucu yağdaki aktif bileşen, geleneksel sentetik herbisitler mezotrion ve sulkotrion gibi p-hidroksifenilpiruvat dioksijenazı (HPPD) hedefleyen doğal bir b-triketon olan leptospermondur [31-33]. Limon otu esansiyel yağı, Cymbopogon citratus Stapf'tan elde edilir. veya% 80'e kadar sitral içeren C. flexuosus D.C., etki modu bitki mikrotübüllerinin polimerizasyonunun bozulmasını içeren organik bir herbisit olarak da ticarileştirilen Agronomy 2020, 10, 1687 3 / 13'tür [34].
Limon otu yağı, bir kontakt herbisit görevi görür ve aktif bileşen yer değiştirmediğinden, sadece sprey çözeltisini alan bitkilerin kısımları etkilenir.
Çam esansiyel yağı ayrıca yabani ot kontrolü için doğal bir herbisit olarak% 10 sulu emülsiyon olarak da satılmaktadır.
Pinus sylvestris L.'nin iğneleri, ince dalları ve kozalaklarının ve Pinus spp.'ye ait çok çeşitli diğer türlerin buharla damıtılmasından elde edilir. ve terpen alkolleri ve sabunlaştırılmış yağ asitlerini içerir. A- ve b-pinen gibi monoterpenler, malondialdehit, prolin ve hidrojen peroksit konsantrasyonunu artırabilir, bu da yabani otlarda lipid peroksidasyonunu ve oksidatif stresin indüksiyonunu gösterir [35,36].
Bu çalışmanın amacı, dört farklı pelargonik asit ürünü, üç uçucu yağ ve iki karışımın (bir pelargonik asit ürünü ve iki uçucu yağ) üç hedef yabancı ot türü, yani sert çavdar (Lolium rigidum) ile etkinliğini değerlendirmek ve karşılaştırmaktı. Gaud.), Steril yulaf (Avena sterilis L.) ve balta (Galium aparine L.).
2. Malzemeler ve Yöntemler 2.1. Bitki Materyali Toplama ve Tohum Ön İşlemi Haziran ayı boyunca sırasıyla Fthiotida, Viotia ve Larisa menşeli kışlık buğday tarlalarından sert çavdar (L. rigidum), steril yulaf (A. sterilis) ve balta (G. aparine) tohumları toplanmıştır. 2019 (Tablo 1).
Her tarlada 20 bitkiden salkım ve tohumlar toplandı ve Agronomi Laboratuvarına (Atina Ziraat Üniversitesi) aktarıldı.
Tablo 1. İncelenen yabancı ot türleri, kökenleri ve tohum toplamanın gerçekleştirildiği coğrafi konumlar. Ortak Ad Bilimsel Ad Başlangıç Konumu Sert çavdar Lolium rigidum Gaud. Fthiotida 39◦08007 ”N, 22◦24056” E Steril yulaf Avena sterilis L. Viotia 38◦24041 ”N, 23◦00040” E Cleaver Galium aparine L. Larisa 39◦25051 ”N, 22◦45047” E İki deney yapıldı farklı pelargonik asit ürünlerinin, uçucu yağların ve doğal herbisit karışımlarının üç hedef yabancı ot türüne karşı etkinliğini değerlendirmek ve karşılaştırmak için iki kez yapıldı ve tekrarlandı.
Toplanan tohumlar havada kurutuldu, harmanlandı, kağıt torbalara yerleştirildi ve sonraki deneysel çalışmalarda kullanılmak üzere oda sıcaklığında saklandı.
Otların tohumlarında ve yarık tohumlarında uyuşukluğu serbest bırakmak için gerçekleştirilen tohum ön-muamele süreçleri farklıydı.
Sert çavdar ve steril yulaf tohumlarında uyuşukluğu serbest bırakmak için, tohumlar 2 diş cımbızla ayrı ayrı çentiklendi ve 6 ile doyurulmuş Whatman No. 1 kağıt filtre diskinin (Whatman Ltd., Maidstone, İngiltere) iki yaprak üzerine Petri kaplarına yerleştirildi. 10 Kasım'da mL distile su. Petri kapları 2–4 ◦C'de (buzdolabı) 7 gün süreyle tutuldu. Daha sonra 2019 yılında gerçekleştirilen ilk deneysel çalışmada hareketsiz tohumlar ekim için kullanıldı. Toplanan toplam ot tohumlarının yaklaşık yarısı, ikinci deneysel çalışmada kullanılmak üzere oda sıcaklığında saklandı. 2020. Balta için tohumlar dikdörtgen saksılara (28 × 30 × 70 cm3) ekildi ve 17 Haziran'da yaklaşık 3-4 cm derinlikte toprağa gömüldü. Tohumların uyuşukluğunu kırmak için saksılar doğal koşullarda 3 ay süreyle dışarıda tutuldu.
19 Eylül'de tohumlar saksılardan dikkatlice çıkarıldı.
Daha sonra, hava ile kurutuldular, birinci veya ikinci deneysel çalışma için kullanılıncaya kadar oda sıcaklığında kağıt torbalarda saklandılar.
İlk denemenin deneyleri sırasında 18 Kasım 2019'da yaklaşık on beş sert çavdar ve steril yulaf tohumu ve yirmi balta tohumu ayrı saksılara (12 × 13 × 15 cm3) ekildi. Sert çavdar ve steril yulaf tohumları 1 cm derinlikte ekildi.
Maksimum fide çıkmasını sağlamak için balta tohumları da 1 cm derinlikte ekildi.
Saksılar, Atina Ziraat Üniversitesi'nin deney sahasından elde edilen herbisit içermeyen toprak ve 1: 1 (v / v) oranında turba karışımı ile doldurulmuştu.
Deney sahasının toprağı pH değeri 7.29 olan killi balçık (CL) iken, CaCO3 ve organik madde içerikleri sırasıyla% 15.99 ve% 2.37'dir.
Ayrıca, NO3 - Agronomy 2020, 10, 1687 4'ün 13 P (Olsen) ve Na + konsantrasyonları sırasıyla 104,3, 9,95 ve 110 ppm idi.
Tüm yabancı ot türlerinin yabancı ot fideleri, püskürtme için uygun fenolojik aşamaya ulaştığında, saksı başına on iki bitki olacak şekilde dikkatlice inceltildi.
Tüm saksılar gerektiği kadar sulanır ve dışarıya yerleştirilir. Saksılar, tüm bitkiler için muntazam büyüme koşulları elde etmek için her 5 günde bir rasgele dağıtıldı.
İlk deneyin süresi ile ilgili olarak 18 Kasım - 28 Aralık 2019 tarihleri arasında gerçekleştirildi.
İkinci deneysel çalışma ile ilgili olarak, kap deneyleri 14 Ocak 2020'de oluşturuldu ve 25 Şubat 2020'ye kadar yürütüldü.
İkinci deneysel çalıştırma için, işlem için gerçekleştirilen karşılık gelenlerle karşılaştırıldığında tohum ön işlemesi ve deney kurulumu ile ilgili olarak aynı eylemler gerçekleştirildi. Deney dönemlerinde Yunanistan için tipik iklim koşulları gözlemlendi.
En yüksek ay sıcaklıkları Kasım, Aralık, Ocak ve Şubat için sırasıyla 21,3, 15,6, 9,2 ve 11,3 ◦C idi.
Aynı aylar için minimum ay sıcaklıkları sırasıyla 14,2, 9,2, 2,1 ve 1,8 ◦C iken, bu aylar için toplam yağış yükseklikleri sırasıyla 120,4, 90,6, 16,4 ve 12,0 mm'dir. 2.2. Deneysel İşlemler Potansiyel bir herbisidal etkiye sahip uçucu yağlarla birlikte birkaç pelargonik asit ürünü kullanılmıştır. Özellikle, PA1 (3Stunden Bio-Unkrautfrei, Bayer Garten, Almanya) ve PA2 (Beloukha Garden, Belchim Crop Protection NV / SA, Technologielaan 7, 1840 Londerzeel, Belçika) Tablo 2'de gösterilen konsantrasyonlarda sadece pelargonik asit içerirken PA3 ve PA4 (Finalsan Ultima, W. Neudorff GmbH KG, Emmerthal, Almanya), maleik hidrazid ile birlikte pelargonik asit içeriyordu (Tablo 2). PA1, PA2, PA3 ve PA4 tedavileri için pelargonik asit karıştırılmadan tek işlem olarak uygulandı. Uçucu yağ uygulaması içeren tedavilerle ilgili olarak, EO1 (Manuka yağı, Leptospermum scoparium, Salvia, Hindistan), EO2 (Limon otu yağı, Cymbopogon citratus, Sheer Essence, Hindistan) ve EO3 (Çam yağı, Pinus sylvestris, Sheer Essence, Hindistan) % 5 konsantrasyonda kullanılır.
Tüm uçucu yağlar,% 5 konsantrasyona ulaşmak için işlemden önce suyla seyreltildi.
Aslında, ticari uçucu yağlar, genellikle hacim başına% 10 veya daha fazla olmak üzere yüksek konsantrasyonlarda uygulanmalıdır [30].
Mevcut çalışmada, bu tür doğal herbisitlerin daha düşük konsantrasyonlarda uygulanmasıyla yeterli yabani ot kontrolünün sağlanıp sağlanamayacağını değerlendirmek için uçucu yağ uygulamasının maliyetini düşürmek için% 5'lik bir ara konsantrasyon seçilmiştir, bu da ekonomik açıdan kabul edilebilir. Tüm herbisit uygulamaları, değişken bir konik nozul ile donatılmış kullanışlı bir basınçlı püskürtücü ile gerçekleştirilmiştir.
Püskürtme 0.3 MPa basınçta gerçekleştirildi ve püskürtme açısı 80 ° idi.
Konik ağızlık ile toprak seviyesi arasındaki yükseklik, tüm deneysel işlemler için 40 cm idi.
Sprey kafası, 1.5 km saat-1'de bitkiler üzerinde hareket edecek şekilde ayarlandı ve cihaz, 200 L ha-1 eşdeğerini verecek şekilde kalibre edildi.
İşlemler, bitkilerin 2–3 gerçek yaprağın fenolojik aşamasına ulaştığı ilk yılın iki çalışması için (16 Şubat 2020'de, ikinci yılın iki çalışması için) 20 Aralık 2019'da uygulandı. Sert çavdar ve steril yulaf için BBCH ölçeğinin 12–13'ü ve balta için BBCH ölçeğinin 13–14. Aşamasına karşılık gelen 3–4 gerçek yaprağın fenolojik aşaması. Saksılar dışarıya yerleştirildi ve yabani ot bitkilerinin yaprakları püskürtme sırasında dikey olarak yönlendirildi.
Deneysel işlemler güneşli bir günde gerçekleştirildi ve püskürtme sırasındaki hava sıcaklığı ilk yıl 16.1 ◦C idi (ikinci yıl için 13.4 C).
Tablo 2. Mevcut çalışmada uygulanan deneysel muameleler (örneğin, doğal herbisitler).
Tedavi Etken Madde İçeriği (g / L) veya (mL / L) Doz Hızı (L / ha) Birim Alan Başına Aktif Madde (g / ha) veya (mL / ha) Kısaltma Kontrolü - - - -
Pelargonik asit 18.67% 18.67 1200 3734 3 PA1 Pelargonik asit% 50 50 1200 10000 3 PA2 Pelargonik asit 3.102% + maleik hidrazid 0.459% 3.102 1200 620.4 3 PA3 Pelargonik asit 18.67% + maleik hidrazid 3% 18.67 1 + 3 1200 3734 3 + 600 3 PA4 Agronomi 2020, 10, 1687 5/13
Tablo 2. Devam. Tedavi Etken Madde İçeriği (g / L) veya (mL / L) Doz Hızı (L / ha) Birim Alan Başına Aktif Madde (g / ha) veya (mL / ha) Kısaltma Manuka yağı% 5 5 2200 1000 4 EO1 Limon otu yağı 5% 5 2200 1000 4 EO2 Çam yağı 5% 5 2200 1000 4 EO3 Pelargonic acid 18.67% + maleic hydrazide 3% + Manuka oil 5% 18.67 1 + 3 1 + 5 2200 3734 3 + 600 3 + 1000 4 M1 Pelargonik asit% 18.67 + maleik hidrazid% 3 + Limon otu yağı% 5 18.67 1 + 3 1 + 5 2200 3734 3 + 600 3 + 1000 4 M2 1 Veriler, dört farklı pelargonik asit formülasyonunun aktif bileşen içerikleriyle ilgilidir . Aktif bileşenler g / L cinsinden ifade edilir. 2
Veriler, üç farklı uçucu yağ formülasyonunun aktif bileşen içerikleriyle ilgilidir.
Aktif bileşenler, mL / L cinsinden ifade edilir. 3 Veriler, birim alan başına dört farklı pelargonik asit formülasyonunun aktif bileşen miktarını gösterir.
Miktarlar g / ha cinsinden ifade edilir. 4 Veriler, üç farklı uçucu yağ formülasyonunun aktif bileşen miktarını gösterir.
Miktarlar mL / ha cinsinden ifade edilir.
2.3. Her Doğal Herbisitin Hedeflenen Yabancı Otlara Karşı Etkinliğinin Değerlendirilmesi Hedeflenen yabancı ot türlerine karşı her bir doğal herbisitin etkinliğini değerlendirmek için, her bir yabani ot türü için saksı başına dört bitkinin kuru ağırlığı ve bitki boyu muameleden 1, 3 ve 7 gün sonra ölçülmüştür. (DAT).
Kuru ağırlığı ölçmek için seçilen bitkiler 60 ◦C'de 48 saat kurutuldu ve ardından kuru ağırlık ölçümleri yapıldı.
Kuru ağırlığı ölçmek için kullanılan ölçek üç ondalık basamak doğruluğuna sahipti ve bitki yüksekliği en yakın cm olarak ölçüldü.
Deneylerin her biri, her bir saksıdaki on iki bitki ile başladı ve 1, 3 ve 7 DAT'ta her bir saksıdan dört bitki çıkarıldı.
Değerlendirme süresi 7 DAT'tan uzun değildi çünkü mevcut deney, doğal herbisitlerin incelenen yabani ot türlerinin her biri üzerindeki yok etme etkisini değerlendirmeye odaklandı. Nekroz seviyeleri veya NDVI değerleri ile ilgili herhangi bir gözlem yapılmamıştır çünkü bunlar gelecekteki deneylerin nesneleri olacaktır. 2.4. İstatistiksel Analiz Her iki deney de yılda iki kez tekrarlandı.
Tüm deneyler, dört kopya ve dokuz deneysel işlemle (PA1, PA2, PA3, PA4, EO1, EO2, EO3, M1 ve M2) tamamen rastgele bir tasarımda gerçekleştirildi.
Deneysel işlemlerin her bir yabancı ot türü üzerindeki etkilerinin değerlendirilmesi için dört kopya saksı kullanılmıştır.
Tüm deneyler için, yabancı ot kuru ağırlığı ve her bir muameleye karşılık gelen bitki boyu değerleri, her yabani ot türü için ayrı ayrı ölçüldü. Bu değerler 1, 3 ve 7 DAT'ta kaydedildi ve muamele edilmemiş kontrol bitkileri için kaydedilen karşılık gelen değerlerin yüzdeleri olarak ifade edildi.
Yıllar boyunca birleştirilmiş bir varyans analizi (ANOVA) ve tüm veriler için çalıştırıldı ve ortalamalar arasındaki farklar, Fisher'ın Korumalı LSD testi kullanılarak% 5 anlamlılık düzeyinde karşılaştırıldı. ANOVA, incelenen yabani ot türlerinin her biri için iki deneysel çalışma boyunca x yıllık önemli bir muamele etkileşimi göstermedi. Böylelikle, her bir yabani ot türü için bitki kuru ağırlığı ve boyunun ortalamaları, iki yıl ve iki deneysel çalışma boyunca ortalandı.
Daha sonra, toplanan veriler ANOVA ile Statgraphics® Centurion XVI kullanılarak ≤% 5 olasılık seviyesinde analiz edildi.
Fisher’s Protected LSD testi, deneysel işlemlerin uygulanmasının, çalışılan yabani ot türlerinin her biri için bitki kuru ağırlığı ve yüksekliği üzerindeki etkilerine ilişkin araçları ayırmak için kullanıldı.
3. Sonuçlar 3.1. Deneysel İşlemlerin L. rigidum Kuru Ağırlığı ve Yüksekliği Üzerindeki Etkileri 1 DAT'ta yapılan ilk ölçümde PA3'ün sert çavdarın kuru ağırlığını kontrole göre% 41 azalttığı, biyokütle azalmasının ise% 13 daha yüksek olduğu fark edildi. PA1 durumunda.
Manuka, limon otu ve çam uçucu yağlarının etkinliği benzerdi.
Manuka yağı ve pelargonik asit karışımı, muamele edilmemiş bitkiler için kaydedilen değerden% 63 daha düşük sert çavdar kuru ağırlığı ile sonuçlanırken, limon otu uçucu yağı ve pelargonik asit karışımının etkinliği benzerdi. 3 DAT'ta gerçekleştirilen ikinci ölçümde, PA3'ün, işlenmemiş kontrole göre% 13 48 daha düşük taze ağırlıktan Agronomy 2020, 10, 1687 6 ile sonuçlandığı ortaya çıktı.
PA4 ve EO3 işlemleri uygulandığında, sert çavdar kuru ağırlığı, kontrolün sırasıyla% 34 ve% 37'sinde kaydedildi.
Manuka yağı, sert çavdar otuna karşı tüm deneysel işlemlerin en yüksek etkinliğini sağladı.
7 DAT'ta gerçekleştirilen son ölçümde, kontrol ile karşılaştırıldığında PA3 için% 47'lik bir biyokütle azalması kaydedildi.
Sert çavdar kuru ağırlığı kontrolün% 30 ve% 33'ünde kaydedildiğinden, PA2 ve çam yağı uygulamasının etkinliği artmıştır.
Limon otu yağı ve pelargonik asit karışımı, kontrol için kaydedilen değere kıyasla% 77 daha düşük kuru ağırlık ile sonuçlandı.
Manuka yağı durumunda kontrol ile karşılaştırıldığında biyokütle azalması% 90 seviyesine ulaştı ve benzeri manuka yağı ve pelargonik asit karışımının etkinliği idi (Tablo 3).
Tablo 3. Doğal herbisitlerin işlemden 1, 3 ve 7 gün sonra (DAT) uygulanmasından etkilenen L. rigidum bitkilerinin kuru ağırlığı ve yüksekliği.
L. rigidum bitkilerinin kuru ağırlık ve boy değerleri% kontrol olarak ifade edildi.
Kontrol Tedavisinin Kuru Ağırlığı (%) 1 DAT 3 DAT 7 DAT 1 DAT 3 DAT 7 DAT PA1 46 b 42 ab 41 b 44 cb 43 b 40 ab PA2 34 d 29 cde 30 cd 38 bcd 27 def 28 cd PA3 59 a 52 a 53 a 63 a 54 a 51 a PA4 41 bcd 37 bcd 37 b 42 bcd 33 cde 35 bc EO1 41 bcd 27 de 10 e 45 b 28 cdef 8 e EO2 42 bc 39 bc 40 b 40 bcd 36 bc 38 bc EO3 38 cd 34 bcd 33 cd 37 de 35 bcd 36 bc M1 37 cd 22 e 6 e 36 e 24 f 7 e M2 36 cd 29 cde 23 d 40 bcd 26 ef 21 d LSD (0.05) 8 10 11 7 8 11 p değeri ** ** *** *** *** ** L. rigidum kuru ağırlık ve yüksekliği için aynı sütundaki farklı harfler, ayrı ayrı, a = % 5 önem seviyesi. **, *** = sırasıyla 0,05, 0,01 ve 0,001'de anlamlı.
1 DAT'da, sert çavdar otu yüksekliği, PA3 uygulandığında işlenmemiş kontrolün% 63'ünde kaydedildi.
Limon otu esansiyel yağı (EO2), PA2 ve PA4 işlemleri, kontrole kıyasla% 58-62 daha düşük yükseklik sağladı.
Manuka yağı ve pelargonik asit karışımının etkinliği ve aynı zamanda çam yağının etkinliği, yukarıda bahsedilen üç muameleye kıyasla benzerdi ve biraz arttı.
3 DAT'ta gerçekleştirilen ikinci ölçümde, PA1 durumunda rijit çavdar yüksekliği kontrolün% 43'ünde kaydedilirken, PA2, PA4 ve EO1'in benimsenmesi kontrole kıyasla% 67-73 ile sonuçlandı.
İşlem görmemiş bitkiler için kaydedilen değere kıyasla yükseklik azaltma% 74-76 seviyesine ulaştığı için kullanılan iki karışımın etkinliği de benzerdi ve bu iki işlem sert çavdar otuna karşı en etkili olanıydı. 7 DAT'da gerçekleştirilen son ölçümde, PA3'ün etkinliği önceki iki ölçüme benzerdi, limon otu ve çam yağı uygulaması kontrole kıyasla% 62-64 daha düşük bitki boyu ile sonuçlandı. Ek olarak, bu işlem durumunda bitki yüksekliği kontrolün% 28'inde kaydedildiği için PA2 daha da etkiliydi.
Manuka yağı ve onun pelargonik asit ile karışımı, sert çavdar bitkisi yüksekliği% 92-93 oranında azaltıldığından, açık ara en etkili tedavilerdi (Tablo 3).
3.2. Deneysel İşlemlerin A. sterilis Kuru Ağırlık ve Boy Üzerindeki Etkileri Steril yulaf ile ilgili olarak, 1 DAT'da PA3'ün kuru ağırlığı kontrole göre% 52 azalttığı gözlenmiştir. PA2 tedavisinin etkinliği PA3'ten önemli ölçüde daha yüksekti. Manuka, limon otu ve çamdan elde edilen uçucu yağlar benzer etkinlik göstermiştir.
Manuka yağı ve pelargonik asit (M1) karışımı, limon otu yağı ve pelargonik asit (M2) karışımından yaklaşık% 6 daha etkiliydi.
3 DAT'ta, PA3 uygulaması yapıldığında steril yulaf kuru ağırlığının kontrolün% 44'ünde kaydedildiği, çam yağı uygulaması altında kaydedilen karşılık gelen değer ise kontrolün% 35'inde kaydedilen Agronomy 2020, 10, 1687 7 olarak kaydedildi.
PA1 ve PA4 muameleleri PA3 muamelesinden daha etkiliyken limon otu ve manuka yağları benzer etkinlik ile karakterize edildi.
En etkili muamele, kontrol ile karşılaştırıldığında kuru ağırlığı% 82 azalttığı için manuka yağı ve pelargonik asit karışımıdır. 7 DAT'ta gerçekleştirilen ölçümün sonuçları, yabani ot biyokütlesi kontrolün% 41'inde kaydedildiği için PA3'ün steril yulaf karşısında en az etkili muamele olduğunu, buna karşılık PA4, PA1, EO2 ve EO3 muameleleri için kaydedilen değerlerin 31 ile 33 arasında değiştiğini açıklığa kavuşturdu. Kontrol yüzdesi. Limon otu yağı ve pelargonik asit karışımının etkinliği önemli ölçüde daha yüksekti.
Manuka yağı, işlenmemiş bitkiler için kaydedilen değere kıyasla,% 90'dan daha yüksek bir biyokütle azalması ile sonuçlanırken, manuka yağı ve pelargonik asit karışımı yabani ot biyokütlesini% 96 oranında azaltmıştır (Tablo 4). Tablo 4. A. sterilis bitkilerinin, işlemden 1, 3 ve 7 gün sonra doğal herbisitlerin uygulanmasından etkilenen kuru ağırlığı ve yüksekliği (DAT). A. sterilis bitkilerinin kuru ağırlık ve boy değerleri, kontrolün% 'si olarak ifade edildi. Kontrol İşleminin Kuru Ağırlığı (%) Yüksekliği (%) 1 DAT 3 DAT 1 DAT 3 DAT 1 DAT 3 DAT PA1 36 bcd 33 bc 33 ab 38 bc 36 b 35 ab PA2 27 e 24 de 23 bc 29 c 27 cde 24 cd PA3 48 a 44 a 41 a 53 a 46 a 42 a PA4 33 cde 30 bcd 31 ab 36 bc 33 bc 32 bc EO1 42 ab 28 bcd 7 de 44 ab 31 bcd 12 ef EO2 36 bcd 31 bcd 32 ab 37 bc 34 bc 34 ab EO3 39 bc 35 b 32 ab 42 b 37 b 35 ab M1 28 de 18 e 4 e 30 c 20 e 8 f M2 34 bcde 25 cde 17 cd 36 bc 25 de 19 de LSD (0.05) 9 8 11 9 7 9 p değeri * ** *** * ** *** A. sterilis kuru ağırlığı ve yüksekliği için aynı sütundaki farklı harfler, ayrı ayrı, her tedavi için ortalamalar arasındaki önemli farkları a =% 5 anlamlılıkla gösterir seviyesi. *, **, *** = sırasıyla 0,05, 0,01 ve 0,001'de anlamlı.
Steril yulaf yüksekliği, PA3 uygulandığında 1 DAT'da görüldüğü gibi kontrolün% 53'ünde kaydedildi.
Steril yulaf yüksekliği, PA4 ve PA1 için kontrolün% 36 ila% 38'i arasında değişirken, neredeyse aynı bitki yüksekliğinde azalma, limon otu esansiyel yağı uygulamasına atfedildi.
Manuka yağı ve pelargonik asit karışımı durumunda işlem görmemiş bitkiler için kaydedilen değere kıyasla yükseklik düşüşünün% 30 olduğu tahmin edildi.
Bu karışım ayrıca limon otu yağı ve pelargonik asit karışımından yaklaşık% 6 daha etkiliydi.
3 DAT'ta PA3, etkinliğinin EO3, PA1 ve PA4 tedavilerinin karşılık gelen değerinden daha düşük olması nedeniyle incelenen tüm tedaviler arasında en az etkili olmaya devam etti.
Manuka ve limon otu uçucu yağları uygulandığında gözlenen bitki boyu değerleri benzerdi.
PA2 uygulaması, kontrole göre% 73 daha düşük steril yulaf yüksekliği ile sonuçlanmıştır.
Limon otu yağı ve pelargonik asit karışımının etkinliği benzerdi, manuka yağı ve pelargonik asitin karıştırılması, steril yulaflara karşı en etkili tedaviydi.
7 DAT'da gerçekleştirilen son ölçüm, PA3'ün en az etkili muamele olduğunu, limon otu ve çam uçucu yağlarının PA3 muamelesinden daha etkili olduğunu doğruladı. Limon otu yağının pelargonik asit ile karıştırılması, yukarıda bahsedilen işlemlerden daha etkiliydi.
Manuka yağı uygulaması daha da etkili olurken, pelargonik asit ile karışımı, kontrole kıyasla% 92 ile kaydedilen en büyük bitki boyunda azalma ile sonuçlandı (Tablo 4). 3.3. Deneysel İşlemlerin G. aparine Kuru Ağırlığı ve Boyu Üzerindeki Etkileri Genel olarak, tüm deneysel işlemler, çalışılan ot yabani otlarına göre yarıklara karşı daha etkiliydi. Özellikle, manuka ve limon otu esansiyel yağları, kontrole kıyasla% 67-70 biyokütle azalması sağlarken, iki karışım için biyokütle azaltımı, kontrole kıyasla Agronomy 2020, 10, 1687 8 arasında 13% 76 ve% 78 arasında değişmiştir. işlemden 24 saat sonra gerçekleştirilen ölçümde gözlemlenmiştir. Tüm pelargonik asit formülasyonlarının etkinliği dikkat çekiciydi. 3 DAT'ta çam yağının sırasıyla manuka ve limon otu uçucu yağlarından% 7 ve% 11 daha etkili olduğu ve iki karışımın etkinliğinin benzer olduğu görülmüştür. PA3 muamelesi yabancı ot biyokütlesini% 90 oranında azaltırken, PA2 muamelesinin uygulanması parçalayıcı bitkileri neredeyse ortadan kaldırdı.
7 DAT'ta limon otu ve çam yağlarının etkinliği benzerdi, oysa manuka yağı artan etkinlik (% 92'ye kadar) ile karakterize edildi.
PA4 ve PA1 işlemleri, işlem görmemiş bitkiler için kaydedilen karşılık gelen değerden% 96-97'lik bir kuru ağırlık azalması ile sonuçlandı. Limon otu yağı ve pelargonik asit karışımı durumunda yabani ot kuru ağırlığı kontrolün% 6'sında kaydedilirken, PA2 ve M1 işlemleri yarma bitkilerini tamamen ortadan kaldırmıştır (Tablo 5).
Tablo 5. G. aparine bitkilerinin, işlemden 1, 3 ve 7 gün sonra doğal herbisitlerin uygulanmasından etkilenen kuru ağırlığı ve yüksekliği (DAT).
G. aparine bitkilerinin kuru ağırlık ve boy değerleri% kontrol olarak ifade edilmiştir.
Kontrol İşleminin Kuru Ağırlığı (%) Yüksekliği (%) 1 DAT 3 DAT 1 DAT 3 DAT 1 DAT 3 DAT PA1 12 def 5 cd 4 d 14 def 6 cd 6 cd PA2 5 f 2 d 0 d 8 f 4 d 0 gün PA3 17 cde 10 bc 8 bc 20 cde 12 bc 11 bc PA4 10 ef 5 cd 3 d 13 ef 6 cd 5 cd EO1 33 a 23 a 8 bc 36 a 27 a 11 bc EO2 30 ab 27 a 25 a 33 ab 29 a 27 a EO3 19 cd 16 b 14 b 21 cd 19 b 18 b M1 22 c 12 b 0 d 25 c 13 bc 0 d M2 24 bc 15 b 6 bc 26 bc 16 b 8 cd LSD (0.05) 8 6 9 8 7 9 p değeri *** *** ** *** *** ** G. aparine kuru ağırlığı ve yüksekliği için aynı sütundaki farklı harfler, ayrı ayrı, her işlem için ortalamalar arasındaki önemli farklılıkları gösterir. =% 5 önem seviyesi. **, *** = sırasıyla 0,05, 0,01 ve 0,001'de anlamlı. Manuka ve limon otu yağları uygulandığında, 1 DAT'ta fark edildiği gibi, balta yüksekliği kontrole kıyasla sırasıyla% 64 ve% 67 daha düşüktü. Manuka yağı ve pelargonik asidin etkinliği, tek başına manuka yağının karşılık gelen değerinden% 11 daha yüksekti ve hatta PA4 ve PA1'in etkinliği daha da yüksekti. PA2 uygulaması, kontrol ile karşılaştırıldığında ot yüksekliğini yaklaşık% 92 azalttığı için incelenen tüm muamelelerin en etkili olanıydı.
İkinci ölçümün sonuçları, balta yüksekliğinin sırasıyla manuka ve limon otu uçucu yağları uygulandığında kontrolün% 27 ve% 29'unda kaydedildiğini ortaya koydu.
Limon otu yağı ve pelargonik asit karışımı, çam yağına benzer etkinlik ile karakterize edilirken, PA3 muamelesi, kontrole kıyasla bitki boyunu yaklaşık% 88 azalttı.
7. DAT'ta limon otu yağı uygulamasının baltaya karşı en az etkili tedavi olduğu, çam yağının ise% 9 oranında daha etkili olduğu görülmüştür. Balta yüksekliği, PA4, PA1 ve M2 muameleleri uygulandığında kontrolün sadece% 5,% 6 ve% 8'inde kaydedildi, manuka yağı ve pelargonik asit karışımı veya PA2 muamelesi yarma bitkilerini tamamen ortadan kaldırdı (Tablo 5). 4. Tartışma Mevcut çalışmanın sonuçları, dört pelargonik asit ürününün farklı yabancı ot türlerine karşı farklı etkililiğini ortaya çıkarmıştır.
Çoğu durumda, balta gibi geniş yapraklı yabani otlar, çim türlerinden daha duyarlıyken, artan pelargonik asit konsantrasyonunun (örneğin, PA2) formülasyonları önemli ölçüde daha etkiliydi. Bulgularımız, Munoz ve ark. [8], tüm pelargonik asit bazlı herbisitlerin Avena fatua (L.) bitkilerini 3 DAT'ta tamamen ortadan kaldırmayı başardığını, buna karşın farklı Agronomy 2020, 10, 1687 9'un 13 pelargonik asidin etkinliği açısından önemli bir fark olmadığını fark edenler formülasyonlar. Pelargonik asidin düşük konsantrasyonlu formülasyonu uygulandığında sert çavdar ve steril yulafın yetersiz kontrolü, pelargonik asitin yalnızca% 2 (v / v) konsantrasyonunda uygulanmasının sağlandığı önceki bir çalışmanın bulguları ile uyumludur. % 20 toplam yabancı ot kontrolü [14]. Bununla birlikte, aynı yazarlar, aynı muamelenin, kadife yaprağı (Abutilon theophrastii Medic.) Gibi geniş yapraklı yabani otları yalnızca% 31 oranında kontrol ettiğini fark ettiler. Çalışmamızda cleaver, pelargonik asit bazlı tedavilerin çoğu tarafından tedaviden 24 saat sonra bile yeterince kontrol edildi.
Ayrıca, 7 DAT'ta, tüm muamelelerin yarma kuru biyokütlesini ve bitki yüksekliğini yeterince düşürdüğü fark edildi.
İklim koşullarının etkinlik üzerindeki olası etkileri ve genel sonuçlar, daha fazla araştırılması gereken bir konudur.
Bizim durumumuzda, ilaçlama öncesi ve sırasındaki hava koşulları saksı deneyleri için elverişli görünse de, pelargonik asit ürünleri iki ot otu türüne karşı dikkate değer bir etkinlik göstermedi. Bu sonuç, püskürtme zamanındaki hava sıcaklığına bağlanabilir. Krauss ve ark. [37], hava koşullarının pelargonik asit ürünlerinin etkinliği üzerindeki etkisi ile ilgili olarak benzerdi.
Her halükarda, bu gelecekteki çalışmalarda sistematik olarak değerlendirilmesi gereken bir hedeftir.
Ek olarak, çeşitli yabancı ot türlerinin yeni sürgünler geliştirebileceğine ve pelargonik asit uygulamasından sonra toparlanabileceğine dair kanıtlar vardır.
Bu nedenle, gelecekteki bir deney için başka bir amaç, daha geniş bir yabani ot türü yelpazesi için 7 DAT'den daha uzun bir vadede ortaya çıkan yabani ot büyütme düzeyini bulmak olacaktır.
Aslında, doğal maddeler bitkilerde sistematik olarak yer değiştirmezler ve çoğu tür için uzun vadeli yabancı ot kontrolü sağlayamazlar.
Bununla birlikte, tekrarlanan muamelelerle yeterli yabancı ot kontrolünün sağlanabileceği zaten bildirilmiştir.
Dahası, farklı yabani ot türlerinin doğal herbisitlerin uygulanmasına tepkilerinin değişkenlik gösterdiği aşikardı.
Bu, çok sayıda yabani ot türü arasında bu tür deneysel işlemlerin etkilerinin karşılaştırılmasına yönelik daha fazla çok faktörlü deneylerin önemini vurgulamaktadır.
Pelargonik asit bazlı herbisitlerin gerçek tarla koşullarındaki etkinliği, keşfedilmemiş büyük bir ilgi alanıdır.
Tarlada yabancı ot kontrolü düzeyini değerlendiren ve bu tür yabancı ot kontrol uygulamalarının benimsenmesiyle uygun olabilecek mahsulleri tanımlayan çok fazla çalışma bulunmamaktadır.
Bununla birlikte, Yunanistan'da Kanatas ve arkadaşları tarafından yapılan daha yakın tarihli bir çalışmada ilginç sonuçlar elde edildi. soya fasulyesi mahsulünü bayat bir tohum yatağına ekmeden önce selektif olmayan yabani ot kontrolü için maleik hidrazid ile birlikte pelargonik asidin uygulandığı. Özellikle, pelargonik asit uygulaması ile kombine edilmiş bayat tohum yatağının, normal tohum yatağına kıyasla yıllık yabani otların yoğunluğunu% 95 oranında azalttığı ortaya çıkmıştır; bu, bu tür pelargonik asit bazlı herbisitlerin, bayat bir tohum yatağındaki yıllık yabani otlara karşı glifosata eşit derecede etkili olabileceğini göstermektedir. bir mahsul oluşturulmak üzere ve ekim öncesi yabancı otların yok edilmesinin faydalarından yararlanmak üzeredir [19].
Bir yandan, eski tohum yatağı hazırlama gibi kültürel uygulamaları içeren entegre yabancı ot yönetimi stratejilerinin, gerçek tarla koşulları altında pelargonik asidin herbisidal potansiyelini en üst düzeye çıkarabileceği görülmektedir.
Sonuç olarak, güçlü ve rekabetçi bir mahsul ekilmek üzereyse, pelargonik asit bazlı herbisitler tarafından garanti edilen yabancı ot kontrolü seviyesi yeterli olabilir.
Son zamanlarda Yunanistan'da, arpanın (Hordeum vulgare L.) sert yulaf otunun sert çavdar otu gibi sorunlu yabani otlara karşı rekabet edebilirliğinin, bu tür organik yabancı ot kontrol uygulamaları ekimden önce uygulanırsa artırılabileceği bildirilmiştir [40].
Öte yandan, nonanoik asit uygulamasından sonra, her iki deney sahasında muameleden bir ve iki gün sonra yabani ot örtüsü azalması ve ayrıca Martelloni ve ark. , yabani ot kontrolü için PA-4 tedavisine benzer bir muamelenin uygulandığı yerlerde.
Bu sonuç için önerilen açıklama, yabani otların doğal herbisitin bir etkiye sahip olması için uygun olmayan büyüme aşamasında olduğuydu.
Önceki araştırmalar, nonanoik asidin kabul edilebilir yabancı ot kontrolü için çok genç veya küçük bitkilere uygulanması gerektiğini bildirmiş ve tekrarlanan uygulamalar önerilmiştir.
Bununla birlikte, mevcut deneyde, doğal bir herbisit ürünündeki pelargonik asit konsantrasyonunun artmasının, otlar için daha verimli kontrol ve geniş yaprakların zar zor ortadan kaldırılmasıyla sonuçlanabileceği gözlemlenmiştir.
Bu bulgu, kullanılan nonanoik asit oranının daha yüksek olması nedeniyle (39 L a.i. ha 1) yabancı ot kapsamı, yoğunluğu ve kuru ot biyokütlesinde orta düzeyde bir azalma gözlemleyen Rowley ve diğerleri tarafından bildirilenlerle uyumludur. Diğer yazarlar Japon uzun otlarında (Microstegium vimineum Trin.)
Agronomy 2020, 10, 1687 11,8 kg a.i. oranında pelargonik asit uygulaması nedeniyle kontrol işlemlerine kıyasla 13 yer kaplamasından 10'u. ha − 1 ve% 5 (v / v) konsantrasyon [44]. Maleik hidrazidin potansiyel rolü ile ilgili olarak, bu, muhtemelen ölçümlerin sadece 7 gün olması ve uzun vadeli bir temelde olmaması nedeniyle bu çalışmada istatistiksel olarak anlamlı değildi.
Bununla birlikte, pelargonik asit içeren ürünlerin maleik hidrazid ile birlikte kullanılması umut verici bir taktiktir.
Maleik hidrazidin sistemik aktiviteye sahip olduğu ve hem floem hem de ksilemde mobilite ile meristematik dokularda yer değiştirebildiği gerçeğiyle bir açıklama yapılabilir.
Etki tarzı tam olarak net olmamakla birlikte, Orobanche spp.'ye ait sorunlu asalak yabancı ot türlerinin kontrolünde etkin bir şekilde kullanılabilir.
Pelargonik asidin herbisidal potansiyelini sınırlayan bir faktörün sistemik aktivitenin olmaması, maleik hidrazidin yabancı ot büyümesini azaltması ve uzun vadeli bir kontrol sağlaması olduğu göz önüne alındığında, bu oldukça önemlidir.
Bu çalışmanın bulguları ayrıca manuka yağının, doğal herbisitlerin sistemik aktivitesini artırma zorluğuyla başa çıkmak için olası bir çözüm olduğunu ortaya koydu.
Pelargonik asit ile karıştırılmasa bile, manuka yağı, diğer uçucu yağlara ve pelargonik asit işlemlerine kıyasla tüm yabani otlara karşı daha yüksek etkinlik göstermiştir. Dayan ve ark. [32], manuka yağının ve ana etken maddesi olan leptospermonun toprakta 7 güne kadar stabil olduğu ve işlemden sonra sırasıyla 18 ve 15 gün yarılanma ömürleri olduğu fark edildi. Bu tür bulgular, manuka yağının sistemik aktivitesini ve ayrıca doğal herbisitlerin kullanımıyla ilgili birçok kısıtlayıcı faktörü ele alan yararlı bir araç olabileceğini göstermektedir. Dayan vd. [32] ayrıca domuz otu (Amaranthus retroflexus L.), kadife yaprağı, tarla gündüz otu (Convolvulus arvensis L.), kenevir sesbania [Sesbania exaltata (Sesbania exaltata) için% 68,% 57,% 93,% 88,% 73 ve% 50 daha düşük biyokütle kaydetti. Raf.) Rydb. eski A.W. Tepe], büyük yengeç otu (Digitaria sanguinalis L.) ve çayır otu (Echinochloa crus-galli LP Beauv.), Limon otu esansiyel yağı ile bir karışımın manuka yağı ile karıştırıldığı ve belirtilen hedeflenen yabani ot türlerine uygulandığında, kontrole kıyasla sırasıyla. yukarıda. Çam ve limon otu uçucu yağları, sert çavdar ve steril yulaf için% 60 ile% 70 arasında değişen bir biyokütle azalması sağlarken, geniş yapraklı türler G. aparine'e karşı daha etkilidir.
Young [45] çalışmasında, çam yağı kontrollü kıllı fiğ (Vicia villosa Roth), geniş yapraklı filaree (Erodium botrys (Cav.) Bertol.) Ve tavşan arpası (Hordeum murinum L.) en az% 83, ancak sarı starthistle (Centaurea solstitialis L.), yumuşak brom (Bromus hordeaceus L.), kontrol hiçbir zaman% 85 seviyesini geçmedi.
Poonpaiboonpipat ve ark. [46], tedaviden sadece 6 saat sonra yaprak solması semptomları gözlendiğinden,% 1.25,% 2.5,% 5 ve% 10 (v / v) konsantrasyonlarda limon otu uçucu yağının ahır otuna karşı fitotoksik olduğu kaydedildi.
Aynı yazarlar, artan uçucu yağ konsantrasyonları altında klorofil a, b ve karotenoid içeriğinin azaldığını fark ettiler, bu da limon otu yağının yabani otların fotosentetik metabolizmasına müdahale ettiğini gösterdi [46].
Bu tür uçucu yağların herbisidal potansiyeli mevcut olmasına rağmen, birçok çalışma, uçucu yağların hiçbir sistemik aktivitesi olmaksızın temas eden herbisitler olarak hareket etmesi nedeniyle sınırlamalar olduğu sonucuna varmıştır [9,30,32,45,46].
Genellikle yaprakların kütiküler tabakasını bozarlar, bu da genç dokuların hızlı kurumasına veya yanmasına neden olur.
Bununla birlikte, yanal meristemler iyileşme eğilimindedir ve yeniden büyümeyi kontrol etmek için ek uçucu yağ uygulamaları gereklidir.
Uçucu yağlar, hektar başına 50 ila 500 L aktif bileşen taşımak için yüksek konsantrasyonlarda uygulanmalıdır [30].
Yabani ot kontrolü için limon otu veya çam esansiyel yağlarının uygulanmasındaki sınırlamalar, esas olarak pelargonik asit bazlı herbisitler durumunda gözlemlenenlere benzerdir.
Manuka yağı, bu yağın sistemik aktiviteye sahip olmasını sağlayan leptospermone dahil olmak üzere çok sayıda doğal b-triketon içerdiğinden diğer uçucu yağlardan farklıdır [47].
Bu çalışmanın en önemli bulgularından biri, manuka yağı ve pelargonik asit karışımının uygulandığı durumda hedeflenen tüm yabancı ot türlerinin tatmin edici bir şekilde kontrol edilmesidir. Bu sinerji, pelargonik asit formülasyonlarının, limon otu ve çam esansiyel yağlarının tek başına kullanıldığı durumlara kıyasla, genel yabancı ot kontrolünde iyileşme ile sonuçlandı.
Bu, bu çalışmanın temel bulgularından biridir ve organik veya sürdürülebilir tarım açısından yabancı ot kontrolünü iyileştirmek için hayati bilgiler sağlar.
Coleman ve Penner'ın [14] bulguları benzerdi, diamonyum süksinat ve süksinik asit ilavesinin bir pelargonik asit formülasyonunun etkinliğini% 200'e kadar artırdığını, l-Laktik asit ve glikolik Agronomi 2020, 10, 1687 11 13 asit, gerçek tarla koşullarında bile pelargonik asit formülasyonlarının kadife yaprağı ve ortak kuzu mama (Chenopodium album L.) üzerindeki etkinliğini% 138'e kadar artırmıştır.
5. Sonuçlar Bugüne kadar, Yunanistan'daki başlıca yabancı ot türlerine karşı çeşitli pelargonik asit ürünlerinin, uçucu yağların ve doğal herbisit karışımlarının herbisidal potansiyelini değerlendiren çalışma bulunmamaktadır.
Bu çalışmanın bulguları, yüksek konsantrasyonlarda pelargonik asit içeren doğal ürünlerin seçilmesinin otların kontrol seviyelerini artırabileceğini ortaya koymuştur.
Bununla birlikte, geniş yapraklı yabani otlar söz konusu olduğunda, doğal ürünlerin uygulanmasının, daha düşük pelargonik asit konsantrasyonuna sahip ürünler uygulandığında bile yeterli yabancı ot kontrolüne yol açabileceği görülmektedir. Mevcut çalışmanın sonuçları ayrıca limon otu ve çam yağının temasla yanan herbisitler olarak davrandığını, manuka yağının ise sistemik bir aktivite gösterdiğini doğruladı.
Manuka yağı ile pelargonik asit arasındaki sinerji ilk kez rapor edilmiştir ve bu çalışmanın temel bulgularından biridir.
Bu eşsiz uçucu yağ, pelargonik asit ile ilişkili sistemik aktivite eksikliğiyle başa çıkabilir ve ekibimiz tarafından daha ileri deneyler devam etmektedir.
Hem organik hem de sürdürülebilir tarım sistemlerinde ve ayrıca farklı toprak ve iklim koşullarında yabani ot yönetimi stratejilerinde doğal herbisitlerin yanı sıra doğal herbisit karışımlarının kullanımını optimize etmek için daha fazla doğal madde ve kombinasyonun değerlendirilmesi için daha fazla araştırmaya ihtiyaç vardır.
Pelargonic Acid, dokuz karbon atomlu, doğal olarak oluşan doymuş bir yağ asididir. Pelargonik asidin amonyum tuzu formu bir herbisit olarak kullanılır.
Pelargonic Acid, bitkinin mumsu kütikülünü soyarak hücre bozulmasına, hücre sızıntısına ve kuruma yoluyla ölüme neden olarak çalışır.
Pelargonik asit, pelargonium yağının esterleri olarak doğal olarak oluşan C9 düz zincirli doymuş bir yağ asididir.
Pelargonik asit, antifungal özelliklere sahiptir ve ayrıca bir herbisit olarak ve ayrıca plastikleştirici ve verniklerin hazırlanmasında kullanılır.
Pelargonik asit, bir antifeedant, bir bitki metaboliti, bir Daphnia magna metaboliti ve bir algal metaboliti olarak rol oynar.
Pelargonik asit, düz zincirli doymuş bir yağ asidi ve orta zincirli bir yağ asididir. Nonanoatın eşlenik asididir. Nonanoik asit, bir nonanın hidritinden türetilir.
γ-nonanolakton, fonksiyonel ana nonanoik aside sahiptir
(8R) -8-hidroksinonanoik asit, fonksiyonel ana nonanoik aside sahiptir
(R) -2-hidroksinonanoik asit, fonksiyonel ana nonanoik aside sahiptir
1-nonanoil-2-pentadekanoil-sn-glisero-3-fosfokolin, fonksiyonel ana nonanoik aside sahiptir
1-oktadekanoil-2-nonanoil-sn-glisero-3-fosfokolin, fonksiyonel ana nonanoik aside sahiptir
2-hidroksinonanoik asit, fonksiyonel ana nonanoik aside sahiptir
2-oksononanoik asit, fonksiyonel ana nonanoik aside sahiptir
7,8-diaminononanoik asit, fonksiyonel ana nonanoik aside sahiptir
8-amino-7-oksononanoik asit, fonksiyonel ana nonanoik aside sahiptir
9- (metilsülfinil) nonamid, fonksiyonel ana nonanoik aside sahiptir
9- (metilsülfinil) nonanoik asit, fonksiyonel ana nonanoik aside sahiptir
9-aminononanoik asit, fonksiyonel ana nonanoik aside sahiptir
9-hidroksinonanoik asit, fonksiyonel ana nonanoik aside sahiptir
9-oksononanoik asit, fonksiyonel ana nonanoik aside sahiptir
N-nonanoilglisin, fonksiyonel ana nonanoik aside sahiptir
etil nonanoat, fonksiyonel ana nonanoik aside sahiptir
heksadekafluorononanoik asit, fonksiyonel ana nonanoik aside sahiptir
metil nonanoat, fonksiyonel ana nonanoik aside sahiptir
nonanal, fonksiyonel ana nonanoik aside sahiptir
nonanoil-CoA, fonksiyonel ana nonanoik aside sahiptir
perfluorononanoik asit, fonksiyonel ana nonanoik aside sahiptir
trimetilsilil nonanoat, fonksiyonel ana nonanoik aside sahiptir
nonanoat, nonanoik asidin eşlenik tabanıdır
nonanoil grubu, nonanoik asitten ikame edici gruptur
asit nonanoik (ro)
Asit nonanoik, asit pelargonik (ro)
asit nonanoique (fr)
Asit nonanoik, asit pélargonique (fr)
acido nonanoico (it)
Acido nonanoico, acido pelargonico (it)
Aċidu nonanoiku, Aċidu pelargoniku (mt)
kwas nonanowy (pl)
Kwas nonanowy, kwas pelargonowy (pl)
kwas pelargonowy (pl)
Kyselina nonanová, kyselina pelargonová (cs)
kyselina nonánová (sk)
Kyselina nonánová (kyselina pelargónová) (sk)
Nonaanhape (et)
Nonaanhape, pelargoonhape (et)
Nonaanihappo (fi)
Nonaanihappo (pelargonihappo) (fi)
nonaanzuur (nl)
Nonaanzuur, pelar-goonzuur (nl)
nonano rūgštis (lt)
Nonano rūgštis, pelargono rūgštis (lt)
Nonanoik asit, Pelargonik asit (hayır)
nonanojska kislina (sl)
Nonanojska kislina, pelargonska kislina (sl)
nonanonska kiselina (saat)
nonanová kyselina (cs)
Nonanska kiselina, pelargonična kiselina (hr)
nonansyra (sv)
Nonansyra, pelargonsyra (sv)
nonansyre (da)
nonansyre (hayır)
Nonansyre og pelargonsyre (da)
Nonansäure (de)
Nonansäure, Pelargonsäure (de)
nonánsav (hu)
Nonánsav, pelargonsav (hu)
Nonānskābe (lv)
nonānskābe (lv)
ácido nonanoico (es)
Ácido nonanoico, ácido pelargónico (es)
ácido nonanóico (pt)
Ácido nonanóico, Ácido pelargónico (pt)
Εννεανικό οξύ (πελαργονικό οξύ) (el)
εννεανοϊκό οξύ (el)
нонанова киселина (bg)
Нонанова киселина, пеларгонова киселина (bg)
CAS isimleri: Nonanoik asit
IUPAC isimleri
Asit C9, Pelargonik asit
ANOİK ASİT
Nonanoik Asit
Nonanoik asit
nonanoik asit
Nonanová kyselina
Nonansäure
Pelargonik asit
Pelargonik ve gerçek yağ asitleri
Ticari isimler
Acido Pelargónico
Pelargonik asit
Prifrac 2913
Prifrac 2914
Prifrac 2915
Eş anlamlı
1-nonanoik asit
1752351 [Beilstein]
267-013-3 [EINECS]
506-25-2 [RN]
Asit C9
Asit nonanoïque [Fransızca] [ACD / IUPAC Adı]
n-nonanoik asit
n-Nonilik asit
Nonanoik asit [ACD / Endeks Adı] [ACD / IUPAC Adı]
Nonansäure [Almanca] [ACD / IUPAC Adı]
n-Pelargonik asit
Pelargonik Asit
RA6650000
Pergonik asit
130348-94-6 [RN]
134646-27-8 [RN]
1-OKTANEKARBOKSİLİK ASİT
4-02-00-01018 (Beilstein El Kitabı Referansı) [Beilstein]
Cirrasol 185A
EINECS 203-931-2
EINECS 273-086-2
Zımpara 1203
Zımpara L-114
http://www.hmdb.ca/metabolites/HMDB0000847
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:29019
Jsp000917
KNA
KZH
MLS001066339
NCGC00164328-01
n-Nonanoik-9,9,9-d3 asit
n-Nonoik asit
Cevapsız
karboksilik olmayan asit
nonoik asit
nonilik asit
Pelarjik asit
sardunya
Pelargon [Rusça]
Pelargon [Rusça]
Pelargonik Asit 1202
Pelargonsaeure
SMR000112203
VS-08541
WLN: QV8
Eşanlamlı Kaynak
1-Nonanoat
1-Nonanoik asit ChEBI
1-Oktankarboksilat
1-Oktankarboksilik asit
CH3- [CH2] 7-COOH
Cirrasol 185a
Zımpara 1202
Zımpara L-114
Emfac 1202
FA (9: 0)
Ürün adı
Nonanoik asit (Pelargonik asit), Yağ asidi
Açıklama
Yağ asidi.
Alternatif isimler
Pelargonik asit
Biyolojik açıklama
Güçlü antifungal ajan (IC50 = Trichophyton mentagrophytes'e karşı 50 μM). Patojenik mantarın spor çimlenmesini ve misel büyümesini engeller. In vivo olarak aktif.
Nonanoik asit artık nispeten yaygın bir şekilde ev bahçesinde bir herbisit olarak kullanılmaktadır. Akut göz tahrişi çalışmasının yakın zamanda yapılan bir değerlendirmesi,% 1.8 nonanoik asit içeren bir ürün formülasyonuna maruz kalmanın ardından orta derecede göz tahrişini gösterdi.
Başvurular
Nonanoik asit, plastikleştiriciler ve verniklerin hazırlanmasında kullanılır. Çimenlerde yabani otların kontrolünde hızlı bir yakma etkisi için yaygın olarak glifosat ile birlikte kullanılır.
Nonanoik asit türevlerinin antimikrobiyal aktivitelerinin araştırılması
Ocak 2006 Freenius Çevre Bülteni 15 (2): 141-143
Özet ve Şekiller
Gelecek vaat eden antimikrobiyal bileşikler için yapılan bir araştırmada, 2, 3, 4, 5, 6, 7 ve 8. pozisyonlarda yedi metil dallı n-nonanoik asit (MNA) türevi sentezlenmiş ve antimikrobiyal aktivite tarif edilmiştir. Bacillus subtilis, Mycobacterium smegmatis, Sarcina lutea, Escherichia coli, Salmonella typhimurium ve Streptomyces nojiriensis'e karşı in vitro mikrodilüsyon broth yöntemi kullanılarak disk difüzyon testleri kullanılarak anti-mikrobiyal aktiviteler belirlenmiş ve n-nonanoik asit için MIC değerleri olarak ifade edilmiştir. Mantarlar için Candida utilis ve Penisilin G ve Polimiksin B ile karşılaştırıldığında Tüm bileşikler, Gram-pozitif bakterilere karşı çeşitli antimikrobiyal aktivite sergiler, ancak iki bileşikte (2-MNA ve 5 -MNA). İlginç bir şekilde, sadece 4-MNA, 7-MNA ve 8-MNA, Streptomyces'e karşı aktiviteye sahiptir.
Eş anlamlı
Pelargonik asit; 1-Oktankarboksilik asit; Cirrasol 185A; Cirrasol 185a; Emfac 1202; Hexacid C-9; Nonoik asit; Nonilik asit; Pelargic asit; Pelargon [Rusça]; n-Nonanoik asit; n-Nonoik asit; n-Nonilik asit; [ChemIDplus]
Kaynaklar / Kullanımlar
Doğal olarak sardunya yağında bir ester olarak bulunur; [Merck Index] Birkaç uçucu yağda bulunur; Verniklerde, ilaçlarda, plastiklerde ve turbojet yağlayıcılar için esterlerde kullanılır; Ayrıca aroma ve koku, flotasyon ajanı, benzin katkı maddesi, herbisit, elma ve armut ağaçları için çiçek inceltici, dezenfektan ve meyve ve sebzeleri soymak için kullanılır; [HSDB] Peroksitler ve gresler yapmak için, alkid reçineleri için bir katalizör olarak, böcek cezbedicilerinde ve topikal bir bakterisit ve fungisit ilacı olarak kullanılır; [CHEMINFO]
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Nonanoik asidin antimikrobiyal bir ajan olarak, özellikle bir antifungal ajan olarak kullanımı
Öz
Buluş, nonanoik asidin bir antimikrobiyal, özellikle antifungal, ajan veya katkı maddesi olarak, özellikle süt ürünleri veya meyve suları gibi yiyeceklerde veya gıdalarda kullanımına ilişkindir.
Buluşun belirli bir yönü nonanoik asit yani bir peynir kaplamasının kullanılmasını içerir.
Buluş ayrıca nonanoik asidin mantar önleyici madde olarak dahil edildiği bir peynir kaplaması ile ilgilidir; böyle bir kaplama ile sağlanmış bir peynir; ve böyle bir kaplamayı uygulamak için nonanoik asit içeren bir bileşim.
Nonanoik asit, özellikle gıdanın yüzeyinde veya yakınında kullanılır veya gıda boyunca 10 - 10.000 ppm, özellikle 100 - 1.000 ppm miktarında homojen olarak dağıtılır. Nonanoik asit ayrıca, substratların veya yüzeylerin, özellikle gıdalarla temas eden substratların veya yüzeylerin işlenmesi için bir antimikrobiyal ajan olarak kullanılabilir; taşıma ve / veya saklama sırasında yiyecekleri, kesme çiçekleri ve soğanları korumak için; dezenfektanlarda ve temizlik maddelerinde; ahşabı korumak veya işlemek için; kozmetik veya cilt bakım ürünlerinde; ve Candida gibi mantar enfeksiyonlarını ve maya enfeksiyonlarını önlemek ve tedavi etmek için farmasötik kompozisyonlarda.
Nonanoik asidin antimikrobiyal bir ajan olarak, özellikle bir antifungal ajan olarak kullanımı
Mevcut buluş, nonanoik asidin bir antimikrobiyal ajan, özellikle bir antifungal ajan olarak kullanımına ilişkindir.
Daha özel olarak, buluş, nonanoik asidin bir antimikrobiyal madde olarak, özellikle bir mantar önleyici madde olarak, gıdalarda ve özellikle peynir gibi süt ürünlerinde ve meyve suları gibi meyveye dayalı ürünlerde kullanımına ilişkindir.
Buluş ayrıca antimikrobiyal bir madde olarak nonanoik asit içeren gıdalarla ilgilidir.
Buluşun belirli yönleri, nonanoik asitin peynir kaplamalarında (çözeltiler veya süspansiyonlar), bu şekilde elde edilen nonanoik asit içeren peynir kaplamalarında ve bu nonanoik asit içeren kaplamalarla kaplanmış peynirlerde kullanılmasıdır.
Nonanoik asidin gıda ürünlerinde kullanımı bilinmektedir.
Örneğin, alkolsüz içecekler, dondurma, şekerleme, jelatin, sütlü tatlılar ve fırıncılık ürünlerinde sentetik bir tatlandırıcı olarak kullanılır.
ABD Patenti 2 154 449, C3 - CI2 karboksilik asitlerin ve bunların tuzlarının mantar önleyici özelliklerini, özellikle ekmek üzerinde küf oluşumunu önlemek için ekmek hamuruna kalsiyum propiyonatın dahil edilmesini tarif eder.
Avrupa Patent Başvurusu EP 0 244 144 A1, diğerlerinin yanı sıra gıda bileşimlerine koruyucu olarak bir veya daha fazla C6.C8 karboksilik asit ile kombinasyon halinde gliseril yağ asidi esterlerinin eklenmesini öğretir.
Uluslararası başvuru WO 96/29895, ürünlerin işlenmesi sırasında ürünlerle temas eden yüzeyleri, ekipmanı ve malzemeleri antimikrobiyal aromatik bir bileşikle işlemden geçirerek çabuk bozulan ürünlerin raf / depolama ömrünü iyileştirmek için bir yöntemi tarif eder.
WO 96/29895, nonanoik asit dahil olmak üzere yağ asitlerinin aromatik bileşik ile kombinasyon halinde de kullanılabileceğini belirtir.
Uluslararası başvuru WO 92/19104, bakteriler ve küflerin neden olduğu bitkilerdeki enfeksiyonları kontrol etmek için nonanoik asit dahil olmak üzere C7 - C20 karboksilik asitlerin kullanımını öğretir.
Avrupa Patent Başvurusu EP 0 022 289, kateterler gibi tıbbi aletlerin üretimi için polimerlere C3-C, karboksilik asitlerin dahil edilmesiyle ilgilidir.
Avrupa Patent Başvurusu EP 0 465 423, C4 - C, 4 karboksilik asit içeren antimikrobiyal farmasötik preparatları tarif eder.
ABD Patenti 4 406 884, C5 - C, 2 karboksilik asit içeren topikal kullanım için antimikrobiyal farmasötik preparatları tarif eder.
ABD Patenti 3 931 413, bitkilerin tomurcuklarında kışı geçiren küflerin neden olduğu enfeksiyonlarla mücadele etmek için bitkilerin C6 - C, 8 karboksilik asitlerle işlenmesini öğretir.
Nonanoik asit ayrıca bazı et ürünlerinde asitliği ayarlamak için kullanılır.
Örneğin, ABD Patenti 4 495 208,% 4-15 (m / m) içeren yüksek nem içeriğine (Aw> 0.9 ve% 50-80 su içeriğine) sahip, iyi depolama / raf ömrüne sahip bir köpek veya kedi mamasını açıklamaktadır. ) fruktoz,% 0.3 - 3.0 (m / m) yenebilir bir organik asit, 3.5 - 5.8 aralığında bir pH elde etmek için yeterli inorganik asit ve bir mantar önleyici madde.
Organik asit tercihen heptanoik asit, oktanoik asit, nonanoik asit veya bunların bir kombinasyonundan seçilir.
ABD Patenti 4 495 208'e göre hayvan yeminde yenebilir organik asit, sorbik asit ve / veya bunların tuzları gibi kendi başına bilinen bir şeker (fruktoz) ve mantar önleyici bir maddenin (antimikotik) yanında her zaman mevcuttur.
Belirtilen miktarlarda bu üç bileşenin kombinasyonunun sinerjik bir bakteri yok edici etki sağladığı belirtilmektedir.
ABD Patenti 3 985 904, yüksek nem içeriğine sahip ve insan tüketimi için veya bir hayvan yemi olarak uygun olan et bazlı bir yiyeceği tarif eder.
Bu yiyeceğin nem içeriği en az yaklaşık% 50 (mm) ve su aktivitesi A ,,, en az yaklaşık 0,90'dır ve öğütülmüş, haşlanmış, protein benzeri tavuktan% 50'den (m / m) fazlasını içerir, balık veya et malzemesi. % 1-35 (m m) nişasta bazlı jelatin benzeri bir dolgu maddesi,% 1.7 ile 3.8 arasında yenilebilir, toksik olmayan bir asit ve etkili miktarda bir mantar önleyici madde.
Yenilebilir organik asit, bu yiyeceğe, gıdanın pH'ını 3,9 ila 5,5 aralığındaki bir değere getirmek için yeterli bir miktarda dahil edilir.
US-A 3 985 904, kolon 6'da çeşitli uygun yenilebilir asitlerden bahsetmesine rağmen, nonanoik asit burada açıkça belirtilmemiştir.
US-A 3 985 904'e göre mantar önleyici madde, benzoatlar, propiyonatlar ve sorbat tuzlarından seçilir.
EP-A 0 876 768, gıdaların depolanma / raf ömrünün iyileştirilmesi için poligliserolün yağlı asit monoesterlerinin kullanımını anlatmaktadır.
Burada yağlı asit kökleri kaproik asit, kaprilik asit, laurik asit veya miristik asitten seçilebilir.
Nonanoik asidin tarımsal kullanım için herbisidal bileşimlerde kullanımı, diğerlerinin yanı sıra, ABD Patentleri 5 098 467, 5 035 741, 5 106 410 ve 5 975 4110'da açıklanmaktadır. ABD Patentleri 4 820 438, 5 330 769 ve 5 391 379 açıklanmaktadır. sabun ve temizlik maddelerinde nonanoik asit kullanımı.
Yukarıdaki literatür alıntılarından hiçbiri, nonanoik asidin, bakterilerin, küflerin ve mayaların büyümesini engellemek için gıdalara güvenli bir şekilde dahil edilebileceğini ve / veya gıdalarda kullanılabileceğini açık bir şekilde tarif etmiyor veya önermiyor. Özellikle, bu literatür alıntılarının hiçbiri nonanoik asidin bu amaçla güvenle kullanılabileceği dozajı öğretmez.
Şu anda, natamisin peynir yapımında antifungal ajan olarak kullanılmaktadır.
Aynı zamanda pimarisin veya "antibiyotik A5283" olarak adlandırılan ve Delvocid® ve Natamax® (diğerlerinin yanı sıra) ticari isimleri altında pazarlanan bu bileşik, Streptomyces natalensis ve S. chattanoogensis'in metabolik bir ürünüdür.
Bununla birlikte, natamisin kullanımının bir takım dezavantajları vardır. Örneğin oldukça pahalıdır.
Üstelik, Penicillium küfünün, natamisin ile muamele edilmiş peynirler üzerinde (yüzeylerinde) büyüyebildiği bulunmuştur.
Bu, özellikle peynir endüstrisinde dezavantajlıdır, çünkü P. discolor, peynir depolarında yaygındır.
Nonanoik asidin, özellikle gıda ürünlerine uygun bir şekilde dahil edilebilecek miktarlarda kullanıldığında antimikrobiyal bir etki, özellikle mantar önleyici bir etki sergilediği bulunmuştur. Daha özel olarak, nonanoik asidin peynir gibi süt ürünlerinde ve meyve suları gibi meyveye dayalı ürünlerde antimikrobiyal bir ajan, özellikle antifungal (fungisidal) ajan olarak avantajlı bir şekilde kullanılabileceği bulunmuştur.
Buluşa göre bulunan nonanoik asidin antimikrobiyal etkisi kısmen şaşırtıcıdır çünkü bazı küf türlerinin (örneğin Aspergillus niger, Synchephalastrum racemosus, Geotrichum candidum, Penicillium expansum, Rhizopus stolonifer ve Mucor plombus) doğal olarak nonanoik asit ürettiği bilinmektedir.
Ek olarak, buluşa göre nonanoik asidin aynı zamanda peynir depolarında da ortaya çıkabilen mayaların gelişimini engelleyebildiği bulunmuştur.
Bu nedenle, bir birinci yönde buluş, antimikrobiyal bir ajan olarak nonanoik asidin (n-oktan-1-karboksilik asit, pelargonik asit, n-nonlik asit), özellikle de yiyeceklerde veya bunlarda antifungal ajan (katkı maddesi) olarak kullanımına ilişkindir. veya mikroorganizmaların neden olduğu bozulmaya karşı korunması gereken diğer ürünler.
Buluş ayrıca nonanoik asit tuzlarının bir antimikrobiyal madde olarak kullanımına ilişkindir.
Buluş ayrıca antimikrobiyal bir ajan olarak nonanoik asit, özellikle antifungal ajan içeren gıdalarla ilgilidir.
Gıda, insanlar veya hayvanlar tarafından, özellikle de insan tüketimi için tüketilmeye uygun herhangi bir madde olabilir ve ya yenmeye hazır bir gıda ürünü ya da bir gıda ürününe dahil edilebilen veya işlenerek bir gıda ürünü elde edilebilen bir bileşen olabilir. Gıda veya gıda ürünü, özellikle bakteriler, mayalar ve özellikle küfler dahil olmak üzere mikroorganizmaların neden olduğu yok olmaya yatkın bir ürün veya maddedir (yani herhangi bir antimikrobiyal ajan eklenmediğinde), örneğin bir madde veya oda sıcaklığından (20-25 ° C) bir sıcaklık gibi, ürünün normal saklama koşulları altında birkaç gün ile birkaç hafta arasında (örneğin 3 gün ila 3 hafta) saklanacak ürün ) buzdolabı sıcaklığına kadar (yaklaşık 4 ° C). Ancak buluş bunlarla sınırlı değildir.
Bu bağlamda nonanoik asit, mikrobiyal büyümeyi, özellikle küf oluşumunu engellemek ve dolayısıyla depolama / raf ömrünü uzatmak için kullanılır.
Örneğin, mikrobiyal büyüme nonanoik asit kullanımıyla geciktirilebilir.
Geciktirme derecesi, diğer şeylerin yanı sıra, yiyeceğe, nonanoik asit konsantrasyonuna, gıdanın depolandığı koşullara (sıcaklık, atmosferik nem), gıdanın maruz kaldığı mikroorganizma türlerine ve yükleme derecesine bağlı olacaktır. .
Küf oluşumu durumunda, küf oluşumu (yani küfün ilk büyümesinin çıplak gözle görülebildiği zaman noktası) genel olarak en az bir gün, tercihen en az 5-7 gün gecikecektir. işlenmemiş yiyeceklere kıyasla yiyeceklerin genellikle depolandığı sıcaklıkta - genellikle oda sıcaklığında (20 ° C) veya buzdolabında (4 ° C) - anlamına gelir. Örneğin, buluşa göre nonanoik asit içeren bir kaplama ile kaplanmış peynir durumunda, ilk farkedilebilir küf oluşumu 60 ila 67 gün arasında ertelendi. Bu bağlamda, aşağıdaki Örnek 1'e ve ayrıca Şekil 1'de verilen sonuçlara atıfta bulunulmaktadır.
Buluşun amaçları doğrultusunda, "küf oluşumunun engellenmesi" ve / veya "mantar önleyici", tercihen ayrıca mayaların gelişiminin de engellendiği anlamına gelir.
Dahası, buluşa göre nonanoik asidin örneğin gıdanın bozulmasına neden olan veya başka şekilde kalitesini düşüren bakterilere ve veya Listeria, Legionella, Salmonella ve E.coli gibi patojenlere karşı da bir antibakteriyel etkiye sahip olduğu tespit edilmiştir. O157, Staphylococcus.
Nonanoik asidin bakteriler üzerindeki (büyümesi) bu inhibe edici etkisi, avantajlı bir şekilde yoğurt gibi fermente edilmiş süt ürünlerinde (hazırlanmasında) da kullanılabilir.
Bu, aşağıda daha ayrıntılı olarak açıklanacaktır. Yiyecek katı, yarı katı veya akışkan bir gıda olabilir ve fermente edilmiş veya fermente edilmemiş bir gıda olabilir.
Nonanoik asidin antimikrobiyal bir ajan, özellikle antifungal ajan olarak buluşa göre kullanılabildiği, sınırlayıcı olmayan birkaç gıda örneği şunlardır: - önceden pişirilmiş ekmek gibi hamur ürünleri dahil, yemeye hazır gıda ürünleri, erişte, makarna, çorbalar ve benzerleri; sosis gibi balık ve et ürünleri ve meyve suları ve konserve meyveler veya meyvelerin (meyve suları) süt ürünleriyle kombinasyonları gibi sebze veya meyveye dayalı ürünler; un; fındık ve (kurutulmuş) güney meyveleri; ve ayrıca önceden hazırlanmış yemekler, diyet gıdaları, tam gıdalar ve bebek maması gibi ürünler; mayonez, ketçap ve benzeri soslar gibi ileri işlemler için yiyecekler ve bileşenler; reçel, marmelat ve benzeri meyve müstahzarları; ve benzerleri. Buluşa göre nonanoik asit ayrıca gıda sektörü dışında antimikrobiyal bir ajan, özellikle antifungal ve / veya antibakteriyel ajan olarak da kullanılabilir ve bunun örnekleri aşağıda verilecektir.
Bu noktada bahsetmeye değer bir örnek, portakal, limon, greyfurt, elma, armut ve ayrıca fındık ve (kurutulmuş) gibi meyvelerin depolanma / raf ömrünü iyileştirmek için nonanoik asit veya nonanoik asit içeren bir kaplamanın kullanılmasıdır. güney meyveleri, kahve, çay, tütün ve benzerleri, özellikle nakliye öncesinde veya sırasında ve / veya uzun süreli depolama sırasında, örneğin bir depoda veya bir meyve deposunda (klimalı olabilir veya olmayabilir).
Buluşa göre mantar önleyici bir madde olarak kullanıldığında, nonanoik asit, küflerin, mayaların ve bakterilerin engellenmesi için etkili bir miktarda kullanılacaktır; bu, kural olarak, özellikle kg gıda başına 1 ila 10.000 mg nonanoik asit olacaktır. Her kg gıda için 10-1.000 mg nonanoik asit ve daha özel olarak her kg gıda için 100-500 mg nonanoik asit.
Bu nedenle, örneğin nonanoik asit, yoğurtta kilogram (kg) yoğurt başına yaklaşık 200 miligram (mg) nonanoik asit miktarında kullanılabilir.
Etkili nonanoik asit miktarı için alt sınır, tercihen her kg gıda için 10, 25, 50 veya 100 mg nonanoik asit serisinden seçilirken, üst sınır tercihen 10.000, 5.000, 2.500 veya 1.000 mg serilerinden seçilir. kg gıda başına nonanoik asit.
Tercihen, bu miktarlar yiyeceğin su içeriğine bağlıdır. Bu nedenle,% 80'lik bir su içeriğine sahip bir gıda olması durumunda, yukarıda bahsedilen miktarlarda nonanoik asitin% 80'i de gıda kg'ı başına ilave edilebilir. Bununla birlikte, kesin nonanoik asit miktarı, amaçlanan yiyeceğe ve nonanoik asidin gıdada kullanılma şekline bağlı olacaktır.
Böylece, nonanoik asit tüm gıda boyunca eşit olarak dağıtılabilir, ancak örneğin - özellikle katı veya yarı katı gıdalar durumunda - esas olarak sadece gıda yüzeyinde veya yakınında, örneğin formda da bulunabilir. nonanoik asit içeren bir antimikrobiyal, özellikle antifungal, kaplama veya yüzey tabakasının veya gıda yüzeyinin nonanoik asit ile işlenmesinin bir sonucu olarak. Bu ikinci durumlarda, tam gıdaya dayalı nonanoik asit konsantrasyonu, düşük (yani yukarıda belirtilen miktarlardan daha düşük) olabilir, ancak bunun için yüzeyde veya yakınında yeterli nonanoik asit bulunur. istenen antimikrobiyal, özellikle antifungal etki.
Genelde, 10 - 10.000 ppm, özellikle 100 - 2.000 ppm miktarlarında nonanoik asidin mevcudiyeti - yani, tüm gıda boyunca lokal ya da homojen olarak - istenen antimikrobiyal, özellikle antifungal etkiyi elde etmek için yeterli olacaktır. Aynı konsantrasyonlarda nonanoik asit - yani tüm gıda boyunca yerel olarak veya tekdüze olarak - kural olarak maya ve / veya bakterilerin büyümesini inhibe etmek ve / veya önlemek için yeterli olacaktır.
Tercih edilen bir yönde gıda ürünü, genel olarak süt veya süt bileşenlerine, özellikle inek sütü veya bileşenlerine dayalı bir gıda olarak tanımlanan bir süt ürünüdür. Süt ürünü özellikle katı, yarı katı veya akışkan olabilen fermente bir süt ürünüdür.
Sınırlayıcı olmayan birkaç örnek, peynir, tereyağı, krema, yoğurt veya yoğurt ürünleridir (örneğin, süt / meyve suyu içecekleri gibi yoğurtlu içecekler), süzme peynir, kefir, sütlü tatlılar ve benzerleridir.
Buluş ayrıca, soslar, hamur işleri, tatlılar, yiyecekler (tam gıda ve bebek maması dahil), atıştırmalıklar (örneğin peynir içeren), et ürünleri gibi süt ürünlerinin dahil edildiği / işlendiği gıda ürünlerinde de kullanılabilir. proteinlerin dahil edildiği jambon olarak), süt tozu ve kahve beyazlatıcıları ve benzerleri.
Peynirde ve özellikle düşük tuz içeriğine (yani% 4'ten az, özellikle% 3'ten az) ve yüksek nem içeriğine (yani% 30 veya daha fazla, özellikle% 40) sahip peynirlerde kullanın. % veya daha fazla) özellikle tercih edilmelidir. Bu, özellikle peynirin yüzeyine nonanoik asit uygulanarak gerçekleştirilebilir.
Böylece buluş, (aynı zamanda) beyaz peynir, ezme peynir ve benzeri ürünlerle de kullanılabilir.
Fermente süt ürününün pH'ı tercihen 3,5 ila 5,5 arasındadır, örneğin peynir için 5,1 - 5,5 aralığında ve yoğurt için 3,9 - 4,4 aralığındadır.
Buluşa göre nonanoik asit ilavesinin bu değere ulaşılmasına bir miktar (genellikle küçük) katkı sağlaması engellenmemesine rağmen, nihai pH, bir kural olarak, fermantasyon işleminin ve muhtemelen bununla ilişkili tampon etkisinin bir sonucu olacaktır.
Tercih edilen başka bir düzenlemede gıda ürünü, sınırlı bir raf ömrüne sahip olan, örneğin süt veya yoğurt gibi süt ürünleri ve meyve sularının işlendiği ürünler gibi bir meyve suyu veya benzer bir içecektir.
Nonanoik asit, antimikrobiyal maddeler, özellikle mantar önleyici maddeler için kendi başına bilinen bir şekilde, yani gıda veya gıda ürününe nonanoik asit veya nonanoik asit içeren bir katkı maddesi ilave ederek veya nonanoik asit veya gıda veya gıda ürününde, hazırlanması sırasında ve / veya sonrasında nonanoik asit içeren bir katkı maddesi. Bu işlem sırasında nonanoik asit, gıda boyunca homojen bir şekilde karıştırılabilir veya dağıtılabilir ve / veya örneğin nonanoik asit püskürtülerek veya fırçalanarak (örneğin sulu bir çözelti şeklinde) daldırılarak ( özellikle peynir) bir nonanoik asit çözeltisi içinde veya nonanoik asit içeren bir kaplama uygulayarak. Bu işlem için örneğin sulu bir nonanoik asit çözeltisi veya süspansiyonu veya başka bir nonanoik asit içeren, tercihen sıvı, 100 - 5.000 ppm, özellikle 200 - 3.000 ppm nonanoik asit içeren ve ayrıca kendi başına bilinen sentetik kaplamalar (örneğin kopolimerlere dayalı) ve / veya gıda maddelerine dayalı kaplamalar (bileşenleri) gibi bir peynir kaplamasının uygulanmasına yönelik çözeltiler için kendiliğinden bilinen tüm bileşenleri içerebilir.
Örneğin - 12.8 kg peynir için 140 gramlık bir kaplamada - kaplamadaki nonanoik asit konsantrasyonu 5.000 ppm (bu, kg peynir başına 49.2 mg nonanoik aside karşılık gelir), 1.000 ppm (9.8 mg / kg peynire karşılık gelir) olabilir. veya 100 ppm (0.98 mg / kg peynire karşılık gelir).
Bu şekilde elde edilen nonanoik asit içeren peynir kaplaması, bu tür nonanoik asit içeren peynir kaplamaları ile sağlanan peynirler ve bu işlemde kullanılan nonanoik asit içeren çözeltiler, buluşun diğer yönlerini oluşturur.
Bu bağlamda, nonanoik asidin bir başka avantajı da, peynir (kaplama) üzerindeki yüzey florasının çok fazla gelişmesini önleyebilmesi ve / veya önleyebilmesidir - bu, peynir kabuğunun olumsuz etkilenmesine yol açabilir - (bu, natamisinin aksine, esasen bakteri büyümesi üzerinde herhangi bir etki yapamaz).
Bir kural olarak nonanoik asit, kendi başına bilinen bir gıdada zaten kullanılan bir veya daha fazla antimikrobiyal, özellikle antifungal katkı maddelerinin yerini almak için kullanılacaktır.
Ek olarak nonanoik asit, bilinen antimikrobiyal ajanların uygun olmadığı veya daha az uygun olduğu yiyeceklerde avantajlı olarak kullanılabilir.
Bu tür uygulamalar için nonanoik asit kullanımı, aksi takdirde gerekli olan sterilizasyon işlemlerine ve / veya benzer antimikrobiyal tedaviye (yani bir antimikrobiyal katkı maddesinin kullanımından başka) bir alternatif oluşturabilir.
Genellikle gıdanın nonanoik asit ile tek bir muamelesi - örneğin nonanoik asit içeren bir kaplamanın uygulanması - istenen antimikrobiyal etkiyi elde etmek için yeterli olacaktır. Bununla birlikte, gıdanın nonanoik asit ile tekrar tekrar işlenmesi engellenmez.
Buluşa göre nonanoik asit, özellikle süt ürünleri ve peynir endüstrilerindeki uygulamalarda, natamisinin yerine özellikle kullanılmaktadır. Bu bağlamda, örneğin, J. Stark tarafından E> e Ware (n) Chemicus, 27 (1997), 173-176'da açıklanan natamisin uygulamalarına atıfta bulunulmaktadır.
Buluşa göre nonanoik asit, tercihen gıda ile oldukça uyumludur, yani buluşa göre nonanoik asit kullanımının, en azından gıdanın tadı, kokusu, kıvamı, pH'ı veya istenen diğer özellikleri üzerinde hiçbir olumsuz etkisi yoktur. gıdanın son kullanım veya tüketimden önce saklanması veya depolanması gereken süre boyunca değil.
Kural olarak bu, gıdanın belirli bir dereceye kadar aside dirençli olması gerektiği, yani en azından yukarıda belirtilen miktarlarda nonanoik asit kullanımıyla elde edilen pH'a dayanabilmesi gerektiği anlamına gelir. Uyumlulukla ilgili olası sorunlar durumunda, ayrı bir nonanoik asit içeren kaplamanın kullanılması bir çözüm sunabilir.
Gıda ayrıca, nonanoik asit ile uyumlu olmaları ve antimikrobiyal etkisini ters yönde etkilememeleri koşuluyla, gıda için bilinen diğer tüm katkı maddelerini de içerebilir. Buluşa göre antimikrobiyal madde olarak nonanoik asit kullanıldığında, kural olarak başka bir antimikrobiyal madde gerekli olmayacaktır ve buluşun bir düzenlemesine göre, gıda esas olarak antimikrobiyal madde olarak, yani belirtilen miktarlarda sadece nonanoik asit içerir. yukarıda (yüzde olarak kütle veya ppm olarak).
Bununla birlikte, nonanoik aside ek olarak, kendi başına bilinen bir veya daha fazla başka antimikrobiyal ajanın, örneğin aşağıda belirtilen ajanlar gibi, mevcut olması tamamen engellenemez. Bu nedenle, "esasen münhasıran", nonanoik asidin hepsinin en az% 80'ini (mm), tercihen en az% 90'ını (m / m) ve daha tercihen en az% 95-99'unu (m / m) oluşturduğu anlamına gelir. antimikrobiyal bileşenler mevcuttur (yani antimikrobiyal bir etki elde etmek için gıdaya eklenir).
Ayrıca, nonanoik asidin, kendi başına bilinen ve nonanoik asit ile uyumlu olan bir veya daha fazla antimikrobiyal ajan ile bir karışım halinde kullanılması mümkündür, muhtemelen bir sinerjistik etki elde edilebilir. Bu durumda - bilinen ajanın kullanımına kıyasla - nonanoik asit, kural olarak, genellikle kullanılan bilinen antimikrobiyal ajanın miktarının bir kısmının yerini alacaktır.
Nonanoik asit, bir kural olarak, bu tür karışımlardaki toplam antimikrobiyal bileşenlerin en az% 30'unu (m / m), tercihen en az% 50'sini (m / m) ve daha tercihen en az% 70'ini (m m) oluşturacaktır.
Buluşa göre nonanoik asit ile kombinasyon halinde kullanılabilen antimikrobiyal ajanların sınırlayıcı olmayan birkaç örneği şunlardır: sorbik asit ve bunun tuzları, benzoik asit ve bunun tuzları, para-hidroksibenzoik asit veya bunun esterleri, propiyonik asit ve bunun tuzları, pimarisin, polietilen glikol, etilen / propilen oksitler, sodyum diasetat, kaprilik asit (oktanoik asit), etil format, tilosin, polifosfat, metabisülfit, nisin, subtilin ve dietil pirokarbonat.
Nonanoik asit ayrıca sitrik asit, asetik asit ve benzeri gibi gıdalar için kabul edilebilir asitler dahil asitliği ayarlamak için maddelerle kombinasyon halinde kullanılabilir. Bu bağlamda, nonanoik asit özellikle gıdayı (bu durumda 2 ila 6 aralığında bir pH'a sahip olabilir) aside dirençli küflere karşı koruyabilir. Bu tür aside dirençli küflerin örnekleri, bunlarla sınırlı olmamak üzere, Penicillium roqueforti, P. carneum, P. italicum, Monascus ruber ve / veya Paecilomyces variotii (örneğin çavdar ekmeğinde meydana gelir); ve Penicillium glandicola, Penicillium roqueforti, Aspergillus flavus, Aspergillus candidus ve / veya Aspergillus terreus (örneğin, ekşi ve / veya tatlı ekşi konserveler gibi asitle korunan ürünlerde bulunur). Daha genel olarak, buluşa göre gıdada nonanoik asidin en azından bir kısmının ve tercihen kayda değer bir oranının çözülmemiş formda bulunması tercih edilir.
Bu bağlamdaki genel kural, ayrışmamış nonanoik asit miktarının daha düşük pH'ta artmasıdır: örneğin, nonanoik asidin yaklaşık% 90'ı, yaklaşık 3,8'lik bir pH'ta ayrışmamış formda mevcuttur.
Buluşun bir yönüne göre nonanoik asit, bu nedenle 2 ila 6, tercihen 3 ila 5,8 veya 4 ila 5,6 aralığında bir pH gibi düşük bir pH'a sahip gıdalarda da kullanılır.
Örneğin, peynir kabuğunun pH'ı 4.8 - 5.3 civarındadır.
Yukarıda açıklanan antimikrobiyal, özellikle antifungal etkiye ek olarak, buluşa göre nonanoik asidin kullanımı ayrıca aşağıdaki diğer avantajları da sağlayabilir: nonanoik asit, hem ayrışmış hem de ayrılmamış formda kararlı bir moleküldür.
Uzun alkil zinciri inerttir ve molekülü zar zor reaktif hale getirir. nonanoik asit, diğerlerinin yanı sıra bitkilerde oluşan doğal bir maddedir; - nonanoik asit gıdalarda kullanım için onaylanmıştır (diğerlerinin yanı sıra FDA tarafından); nonanoik asit, gıda ürünleri için işlem aşamalarının / işlemlerinin çoğunda stabil kalır; nonanoik asit, UV ışığına, örneğin natamisine göre daha az duyarlıdır; nonanoik asit, metalik formdaki metallerin varlığında stabildir; - nonanoik asit ısıtma altında stabildir.
Buluş, tercih edilen bir düzenlemesine atıfta bulunularak yukarıda açıklanmıştır; yani gıdalarda, özellikle süt ürünlerinde kullanım.
Bununla birlikte, teknolojide tecrübeli kişiler, nonanoik asidin gıda sektörü dışında mantar önleyici, maya önleyici ve / veya antibakteriyel bir madde olarak da kullanılabileceğini açıklayacaktır. Bu bağlamda, özellikle nonanoik asidin gıdalarda kullanım için onaylanmış olması bir avantaj olacaktır, böylece cilt gibi gıdalarla veya insan vücuduyla temas edebileceği uygulamalarda kullanılabilir.
Bir dizi olası, sınırlayıcı olmayan uygulama şunlardır: hem evsel hem de endüstriyel uygulamalar için dezenfektan (lar), temizlik maddesi (maddeleri) ve benzerleri olarak veya içinde kullanım; taşıma bantlarının, paletlerin ve benzerlerinin dezenfeksiyonu ve / veya temizlenmesi (önleyici işlem dahil); kesme makineleri, karıştırıcılar, karıştırıcılar, ayırma ekipmanları, doldurma makineleri ve gıda işleme endüstrisinden diğer ekipmanlar gibi gıdalarla temas eden cihazların, ürünlerin ve / veya yüzeylerin dezenfeksiyonu ve / veya temizliği (önleyici işlem dahil); fıçılar, tabaklar, tanklar, tabaklar, kaplar ve diğer tutucular; ve ayrıca tezgahlar, lavabo üniteleri ve benzerleri; hem evsel hem de endüstriyel; Özellikle gıda ürünlerinin işlendiği ve / veya depolandığı alanlar, örneğin dolaplar, buzdolapları, mutfaklar, fabrika alanları, nakliye alanları, depolar gibi kapalı olabilecek veya olmayabilecek alanların dezenfeksiyonu ve / veya temizliği (önleyici işlem dahil) ve benzerleri (hem evsel hem de endüstriyel); ve özellikle peynir ambarları ve P. discolor'un meydana gelebileceği diğer ticari tesisler; örneğin plastik, kağıt, karton veya şekilli karton gibi malzemelerden yapılmış yiyecekler (meyve, sebze, peynir ve benzeri gibi) için ambalajın kaplanması ve / veya (önleyici) işlenmesi; portakal, limon, greyfurt, elma, armut gibi meyvelerin korunması; fındık ve
(kurutulmuş) güney meyveleri, kahve, çay, tütün ve benzerleri ve ayrıca kesme çiçek ve soğanlar, küflere ve / veya bakterilere karşı, nakliye öncesinde veya sırasında ve / veya (uzun süreli) depolama sırasında, örneğin bir depoda veya (isteğe bağlı olarak) klimalı bir meyve deposunda; örneğin nemin bir sonucu olarak küf oluşumunu önlemek veya buna karşı koymak için örneğin çadırların veya brandaların ve ayrıca iç mekanların (örneğin duvarlarda) dezenfeksiyonu ve / veya temizliği (önleyici işlem dahil); ahşap ve benzeri malzemelerin korunması ve / veya işlenmesi; kozmetik ve cilt bakım ürünlerinde kullanım; örneğin mantar enfeksiyonlarını ve Candida gibi maya enfeksiyonlarını önlemek ve tedavi etmek için farmasötik uygulamalar için kullanım. Genel olarak buluşun bu yönleri, küf oluşumuna duyarlı olan veya bir küf ve / veya bunun sporları tarafından kirletilebilen veya enfekte edilebilen bir yüzey veya substratın, etkili bir antifungal içeren bir miktarda nonanoik asit ile işlenmesini içerir. ve / veya antibakteriyel etki.
Bu miktar, uygulamaya ve nonanoik asidin yüzey veya substrat üzerinde kullanılma şekline bağlı olarak farklılık gösterecektir.
Bir kural olarak, 10 - 10.000 ppm, özellikle 100 - 2.000 ppm miktarlarında nonanoik asidin mevcudiyeti, bazı uygulamalarda daha yüksek konsantrasyonlar kullanılabilmesine rağmen, bir antimikrobiyal, özellikle antifungal etki elde etmek için yeterli olacaktır. Nonanoik asit, nonanoik asit içeren bir kaplama uygulayarak veya nonanoik asitle püskürtme veya fırçalama (örneğin sulu bir çözelti şeklinde) gibi herhangi bir uygun şekilde yüzey veya substrat üzerinde kullanılabilir. nonanoik asit içeren atomize bir spreyin kullanılması.
Bu tedavi isteğe bağlı olarak tekrar edilebilir.
Bu bağlamda, nonanoik asit bir kez daha, öngörülen uygulama için bilinen dezenfektanların yerine veya bunlarla birlikte ve ayrıca öngörülen uygulama için alışılmış diğer maddeler veya bileşenler ile kombinasyon halinde kullanılabilir. Bu uygulamalar için nonanoik asit ve diğer herhangi bir bileşen isteğe bağlı olarak uygun bir kap içinde, örneğin bir şişe veya bir sprey şeklinde pazarlanabilir.
Buluşa göre nonanoik asidin özel bir uygulaması ayrıca yoğurt gibi fermente gıda ürünlerinin hazırlanması gibi fermentasyon işlemleri sırasında bakteri büyümesinin kontrolü - özellikle inhibisyonu - ile ilgilidir. Bu uygulama için, özellikle nonanoik asidin antibakteriyel etkisinden yararlanılır. Örneğin nonanoik asit, bu tür fermentasyon işlemleri sırasında veya sonrasında pH'ı kontrol etmek için ve özellikle örneklerde daha detaylı olarak açıklandığı gibi örneğin yoğurdun post-asitlenmesini önlemek ve / veya azaltmak için kullanılabilir.
Sonuç olarak yoğurdun tadı daha uzun süre korunur.
Ek olarak buluşa göre antimikrobiyal, özellikle antifungal etki de elde edilecektir.
Buluş şimdi aşağıdaki sınırlayıcı olmayan örneklere ve şekillere atıfta bulunularak açıklanacaktır, burada:
Şekil 1, nonanoik asidin Gouda peyniri üzerindeki küf oluşumu üzerindeki etkisinin gösterildiği bir grafiktir (küf oluşumunun görünür yoğunluğuna karşı zaman); Şekil 2 nonanoik asidin (pelargonik asit) 7 ° C'de yoğurt bakterilerinin gelişimi üzerindeki etkisini gösteren bir grafiktir (bakteri sayısına karşı zaman); -
Şekil 3, nonanoik asidin (pelargonik asit) yoğurdun 7 ° C'de asitlenme sonrası etkisini gösteren bir grafiktir (pH'a karşı zaman); Şekil 4 nonanoik asidin (pelargonik asit) 32 ° C'de yoğurt bakterilerinin gelişimi üzerindeki etkisini gösteren bir grafiktir (bakteri sayısına karşı zaman); Şekil 5 nonanoik asidin (pelargonik asit) 32 ° C'de yoğurdun asitlenme sonrası etkisini gösteren bir grafiktir (pH'a karşı zaman);
Şekil 6, nonanoik asidin (pelargonik asit) peynir kabuğu üzerindeki yüzey florasının gelişimi üzerindeki etkisini gösteren bir grafiktir (bakteri sayısına karşı zaman); Şekil 7, nonanoik asidin (pelargonik asit) D. hansenii, S. cereviseae, C. lipolytica ve R. rubra gelişimi üzerindeki etkisini gösteren bir grafiktir (sayıya karşı zaman);
Şekil 8 A ve 8B, sırasıyla natamisin (Şekil 8 A) ve nonanoik asidin (Şekil 8B) P. discolor'un peynir kabuğu blokları üzerindeki büyümesinin engellenmesi üzerindeki etkisini gösteren fotoğraflardır;
Şekil 9, nonanoik asidin çorbadaki Bacillus cereus büyümesi üzerindeki etkisini gösteren bir grafiktir (bakteri sayısına karşı zaman);
Şekil 10, çorbada nonanoik asidin Staphylococcus aureus büyümesi üzerindeki etkisini gösteren bir grafiktir (bakteri sayısına karşı zaman);
Şekil 11, nonanoik asidin bir süt / meyve suyu içeceğinde Debaromyces hansenii büyümesi üzerindeki etkisini gösteren bir grafiktir (hücre sayısına karşı zaman); Şekil 2, nonanoik asidin bir süt / meyve suyu içeceğinde Penicillium italicum'un büyümesi üzerindeki etkisini gösteren bir grafiktir (hücre sayısına karşı zaman).
Deneysel
Örnek 1: Gouda peynirinde nonanoik asit kullanımı
Gouda peynirlerinin deneme üretimi yapıldı. Bu peynir partisinde bir seri 1000 ppm nonanoik asit (nonanoik asit) ile muamele edildi ve diğer seri bir fungisit (boş) ile muamele edilmedi. İki seri, P. discolor küfü sporları (0.1 spor / cm2) ile aşılandı ve 13 ° C'de ve% 88 bağıl nemde saklandı. Tüm tek tek peynirler, küf mevcudiyetinin derecesi açısından sık aralıklarla görsel olarak değerlendirildi. Aşağıdaki ölçek, görünür kalıpların yoğunluğunun optik değerlendirmesi için kullanıldı;
0 = küf yok 1 = biraz küf
2 = farklı kalıp
3 = önemli ölçüde küf
4 = çok önemli ölçüde küf veya küfle aşırı büyümüş.
Sonuçlar, Şekil 1'de şematik olarak gösterilmektedir. Fungisit içermeyen peynirler durumunda, hafif küf büyümesi (yoğunluk 1), yaklaşık 60 gün sonra tespit edilebildi.
Nonanoik asit ile muamele edilen peynir serisi durumunda, küf büyümesinin (yoğunluk 1) gözlenmesinden 66 gün önceydi.
Örnek 2: Asitlenmeyi önlemek için yoğurtta nonanoik asit kullanımı Bir deneyde, taze hazırlanmış yoğurda çeşitli konsantrasyonlarda nonanoik asit ilave edildi.
Bir seri, kültür sıcaklığında (doldurma, 32 ° C) 8 saat izlendi ve bir başka seri, 7 ° C'de (buzdolabı sıcaklığı) 14 gün süreyle inkübe edildi.
Bu, nonanoik asidin yoğurt fermantasyonu sırasında ve / veya doldurulmuş yoğurt paketlerinin depolanması sırasında ne kadar etkili olduğunu araştırmak için yapılmıştır.
Her iki seri için de pH ve yoğurt bakteri sayısı belirlendi.
Sonuçlar, Şekil 2-5'te gösterilmektedir. 1.000 ppm nonanoik asit eklenmesi, asidifikasyon sonrası (32 ° C) önemli ölçüde önlemiştir ve yoğurt bakteri sayısı 2 log birim azaltılmıştır. 7 ° C'de, daha düşük nonanoik asit içeriklerinde (200 ppm) asitleştirme sonrası üzerindeki bir etki zaten tespit edilebiliyordu. 1.000 ppm eklenmesi asitleşmeyi önledi Buzdolabı sıcaklığında saklandığında neredeyse tamamen ve yoğurt bakteri sayısı 4 log birim azaldı.
Örnek 3: Nonanoik asidin peynir kabuğunun yüzey florası üzerindeki etkisi
Nonanoik asidin peynir kabuğu üzerindeki yüzey florasına etkisi belirlendi.
Sonuçlar (bakteri sayısına karşı süre) Şekil 6'da gösterilmektedir.
Nonanoik asidin (pelargonik asit) D. hansenii, S. cereviseae, C. lipolytica ve R. rubra gelişimine etkisi de belirlendi.
Sonuçlar (sayıya karşı süre) Şekil 7'de gösterilmektedir.
Örnek 4: Peynir kabuğu bloklarında kullanım
Bu deneyde, peynir kabuğu blokları P. discolor ile aşılanmıştır. Bloklar, 20 ° C'de ve yüksek bağıl nemde (% 95) inkübe edildi. Bu koşullar, kalıba optimum büyüme fırsatı sağlamak için kullanıldı ve bu nedenle, peynirin olgunlaştırılması için olağan koşullardan daha serttir.
Sonuçlar, P. discolor ile aşılamadan iki hafta sonra alınan peynir kabuğu bloklarının fotoğraflarını gösteren Şekil 8'de verilmektedir.
Bir seri natamisin (Şekil 8A) ile ve diğer seri nonanoik asit (Şekil 8B) ile muamele edilmiştir.
Nonanoik asit ile muamele edilen bloklarda 2 hafta sonra küf oluşumunun engellendiği açıkça görülebilmektedir.
Örnek 5: Çorbada kullanım
Bu deneyde maydanozlu kremalı mantar çorbası (Albert Heijn şarküteri firmasından Mart 2000'de elde edilen soğuk-taze ürün) ile aşılanmıştır.
104 CFU / ml (ml çorba başına koloni oluşturan birimler) Bacillus cereus (NIZO B443) veya 104 CFU / ml Staphylococcus aureus (NIZO B1211).
Daha sonra çorba, artan konsantrasyonlarda nonanoik asit (100, 500 ve 1,000 ppm) olmadan ve bununla birlikte 20 ° C'de inkübe edildi.
Örnekler, Şekil 9 ve 10'da belirtilen zamanlarda alınmıştır (B. cereus için Şekil 9 ve S. aureus için Şekil 10).
Her bir numuneden, CFU / ml çorba sayısını belirlemek için bir dizi seyreltme kaplanmıştır.
B. cereus örnekleri, mannitol yumurta sarısı polimiksin agarı (MYP) üzerine kaplandı ve 30 ° C'de 24 saat inkübe edildi; S. aureus örnekleri Baird-Parker yumurta sarısı tellürit agar (BP) üzerine plakalandı ve 37 ° C'de 48 saat inkübe edildi. Sonuçlar Şekil 9 ve 10'da gösterilmektedir. Çorbaya 100 ppm nonanoik asit ilavesi, hem B. cereus hem de S. aureus'un büyümesi üzerinde hafifçe inhibe edici bir etkiye sahipken, 500 veya 1.000 ppm nonanoik asit ilavesiyle her iki bakterinin de büyümesi neredeyse tamamen engellenir. Örnek 6: Süt / meyve suyu ürününde kullanın
Bu deneyde bir süt / meyve suyu içeceği (Albert Heijn'den temin edilen Coberco'dan "Milk & Fruit" ™; "Milk & Fruit" ™ soğutulmuş-taze, pastörize edilmiş, koruyucu içermeyen,% 80 yoğurt içme ve% 20'den oluşan bir üründür. ananas suyu 4.0 pH değerine sahiptir) 102 CFU / ml Debaromyces hansenii (NIZO F937) veya Penicillium italicum (CBS 278.58) ile aşılanmıştır.
Süt / meyve suyu içeceği daha sonra nonanoik asit (100, 500 ve 1.000 ppm) olmadan ve artan konsantrasyonlarda 20 ° C'de inkübe edildi.
Örnekler, Şekil 11 ve 12'de belirtilen zamanlarda alınmıştır (D. hansenii için Şekil 11 ve P. italicum için Şekil 12).
CFU / ml içecek sayısını belirlemek için her numune için bir dizi seyreltme kaplanmıştır.
Örnekler, oksitetrasiklin glukoz maya agarı (OGY) üzerine kaplandı ve 25 ° C'de 5 gün süreyle inkübe edildi.
Sonuçlar Şekil 11 ve 12'de gösterilmektedir. 100 ppm nonanoik asidin eklenmesi, D. hansenii'nin büyümesinin tam inhibisyonunu sağlar.
100 veya 500 ppm eklenmesi, P. italicum'un büyümesini inhibe eder ve 1.000 ppm nonanoik asit eklenmesi, 6 güne kadar P. italicum'un büyümesinin tam inhibisyonunu sağlar.
KARBOKSİLİK ASİTİN GENEL AÇIKLAMASI
Karboksilik asit, molekülleri karboksil grubu içeren ve yoğunlaştırılmış kimyasal formül RC (= O) -OH'ye sahip organik bir bileşiktir, burada bir karbon atomu bir katı bağ ile bir oksijen atomuna ve bir hidroksil grubuna tek bir bağ ile bağlanır), burada R, bir hidrojen atomu, bir alkil grubu veya bir aril grubudur. Aldehit oksitlenirse karboksilik asitler sentezlenebilir. Aldehit, birincil alkolün oksidasyonu ile elde edilebilir. Buna göre karboksilik asit, birincil alkolün tam oksidasyonu ile elde edilebilir. Çeşitli Karboksilik asitler doğada bol miktarda bulunur ve birçok karboksilik asidin kendi önemsiz isimleri vardır. Örnekler tabloda gösterilmiştir. İkame isimlendirmede, isimleri, ana bileşiğin ismine son ek olarak -oik asit 'eklenerek oluşturulur. Karboksilik asidin ilk karakteri, sulu çözelti içinde H + katyonlarına ve RCOO-anyonlarına ayrışmadan kaynaklanan asitliktir. İki oksijen atomu elektronegatif olarak yüklenir ve bir karboksil grubunun hidrojeni kolayca çıkarılabilir. Karboksilik grubun yanında elektronegatif grupların varlığı asitliği arttırır. Örneğin trikloroasetik asit, asetik asitten daha güçlü bir asittir. Karboksilik asit, hidroksil hidrojenin zayıf asitliğinden veya karbon ve oksijen arasındaki elektronegatiflik farkından dolayı birçok kimyasal türevi hazırlamak için bir ana malzeme olarak faydalıdır. Hidroksil oksijen-hidrojenin kolay ayrışması, bir alkol ile bir ester oluşturmak ve bir alkali ile suda çözünür bir tuz oluşturmak için reaksiyonlar sağlar. Karboksilik asit ve su üreten alkol arasında esterleşme adı verilen yoğunlaşma reaksiyonu ile neredeyse sonsuz esterler oluşur. İkinci reaksiyon teorisi, karboksil grubunun elektron eksikliği olan karbon atomuna elektronların eklenmesidir. Bir başka teori de dekarboksilasyondur (karbon dioksitin karboksil grubundan uzaklaştırılması). Karboksilik asitler, genellikle hedef bileşikler olmayan asil halojenürleri ve asit anhidritleri sentezlemek için kullanılır. Sentez esterleri ve amidler için ara ürün olarak, biyokimyada ve endüstriyel alanlarda karboksilik asitten önemli türevler olarak kullanılırlar. Karboksilik asitlerden elde edilen neredeyse sonsuz esterler vardır. Esterler, suyun bir asit ve bir alkolden çıkarılmasıyla oluşturulur. Karboksilik asit esterleri, çeşitli doğrudan ve dolaylı uygulamalarda olduğu gibi kullanılır. Alt zincir esterler, aroma verici baz malzemeleri, plastikleştiriciler, çözücü taşıyıcılar ve birleştirme maddeleri olarak kullanılır. Daha yüksek zincirli bileşikler, metal işleme sıvıları, yüzey aktif maddeler, yağlayıcılar, deterjanlar, yağlama maddeleri, emülgatörler, ıslatma maddeleri, tekstil muameleleri ve yumuşatıcılarda bileşenler olarak kullanılır. Ayrıca, çeşitli hedef bileşiklerin üretimi için ara ürünler olarak da kullanılırlar. Neredeyse sonsuz esterler, uygun uygulama seçimleri için çok çeşitli viskozite, özgül ağırlık, buhar basıncı, kaynama noktası ve diğer fiziksel ve kimyasal özellikler sağlar. Amidler, bir karboksilik asitlerin bir amin ile reaksiyonundan oluşur. Karboksilik asidin amino asitleri bağlama reaksiyonu, doğası gereği, tüm hücrelerin protoplazmasının temel bileşenleri olan proteinleri (amid) oluşturmak için geniştir. Poliamid, çeşitli naylon ve poliakrilamid türleri gibi tekrarlanan amid grupları içeren bir polimerdir. Karboksilik asit hayatımızın içindedir.
ALİFATİK KARBOKSİLİK ASİTLER
YAYGIN İSİM
SİSTEMATİK AD
CAS RN
FORMÜL
ERİME NOKTASI
Formik Asit Metanoik asit 64-18-6 HCOOH
8.5 C
Asetik Asit Etanoik asit 64-19-7 CH3COOH
16.5 C
Karboksietan Propiyonik Asit 79-09-4 CH3CH2COOH
-21.5 C
Butirik Asit n-Butanoik asit 107-92-6 CH3 (CH2) 2COOH
-8 C
Valerik Asit n-Pentanoik Asit 109-52-4 CH3 (CH2) 3COOH
-19 C
Kaproik Asit n-Heksanoik Asit 142-62-1 CH3 (CH2) 4COOH
-3 C
Enanthoik Asit n-Heptanoik asit 111-14-8 CH3 (CH2) 5COOH
-10.5 C
Kaprilik Asit n-Oktanoik Asit 124-07-2 CH3 (CH2) 6COOH
16 C
alfa-Etilkaproik Asit 2-Etilheksanoik Asit 149-57-5 CH3 (CH2) 3CH (C2H5) COOH
-59 C
Valproik Asit 2-Propilpentanoik Asit 99-66-1 (CH3CH2CH2) 2CHCOOH
120 C
Pelargonik Asit n-Nonanoik Asit 112-05-0 CH3 (CH2) 7COOH
48 C
Kaprik Asit n-Dekanoik Asit 334-48-5 CH3 (CH2) 8COOH
31 C
Nonanoik asit, esterler sardunya yağı olduğu için doğal olarak oluşan bir yağ asididir. Tatlandırıcı olarak metil nonanoat gibi sentetik esterler kullanılır. Pelargonik asit, bir karboksilik asit içinde sona eren dokuz karbonlu bir zincirden oluşan organik bir bileşiktir. Hoş olmayan, ekşimiş bir kokuya sahip yağlı bir sıvıdır. Suda neredeyse çözünmez, ancak kloroform ve eterde iyi çözünür.
Pelargonik asit olarak da adlandırılan nonanoik asit, CH3 (CH2) 7CO2H yapısal formülüne sahip organik bir bileşiktir. Dokuz karbonlu bir yağ asididir. Nonanoik asit, hoş olmayan, ekşimiş bir kokuya sahip renksiz yağlı bir sıvıdır. Suda neredeyse çözünmez, ancak organik çözücülerde çok çözünür. Nonanoik asidin esterleri ve tuzları nonanoatlar olarak adlandırılır. Kırılma indisi 1.4322'dir. Kritik noktası 712 K (439 ° C) ve 2,35 MPa'dır.
PELARGONIC ACID = NONANOIC ACID = NONYLIC ACID = PELARGIC ACID
EC / List no.: 203-931-2
CAS no.: 112-05-0
Mol. formula: C9H18O2
Nonanoic acid (frequently referred to as pelargonic acid) is a naturally occurring carboxylic acid with a carbon chain-length of nine, belonging to the chemical class of saturated fatty acids commonly referred to as medium chain fatty acids (C8 to C12).
Pelargonic acid is a clear, colourless liquid with a weak odour.
Pelargonic acid (Nonanoic acid) is soluble in aqueous solutions however it can readily form esters and partially dissociate into the pelargonate anion (CH3(CH2)7COO-) and the hydronium cation (H3O+) in an aqueous solution. The molecular weight (158.24 g/mol) and octanol-water partition coefficient (3.4 logPow) of nonanoic acid suggest that dermal penetration is possible.
Nonanoic acid is a medium-chain saturated fatty acid.
Nonanoic acid inhibits mycelial growth and spore germination in the plant pathogenic fungi M. roreri and C. perniciosa in a concentration-dependent manner.It has herbicidal activity against a variety of species, including crabgrass.
Nonanoic acid has been used as an internal standard for the quantification of free fatty acids in olive mill waste waters.
Formulations containing nonanoic acid have been used in indoor and outdoor weed control and as cleansing and emulsifying agents in cosmetics.
Pelargonic acid, also called nonanoic acid, is an organic compound with structural formula CH3(CH2)7CO2H.
Pelargonic acid is a nine-carbon fatty acid. Nonanoic acid is a colorless oily liquid with an unpleasant, rancid odor.
Pelargonic acid is nearly insoluble in water, but very soluble in organic solvents.
The esters and salts of pelargonic acid are called pelargonates or nonanoates.
Pelargonic acid is used in herbicide formulations and in the preparation of plasticizers, resins, lubricants, and lacquers
Pelargonic acid or Nonanoic Acid is a C9 straight-chain saturated fatty acid which occurs naturally as esters of the oil of pelargonium.
Pelargonic acid has antifungal properties, and is also used as a herbicide as well as in the preparation of plasticisers and lacquers.
Nonanoic Acid is a naturally-occurring saturated fatty acid with nine carbon atoms. The ammonium salt form of nonanoic acid is used as an herbicide.
Nonanoic Acid works by stripping the waxy cuticle of the plant, causing cell disruption, cell leakage, and death by desiccation.
Nonanoic acid is a C9 straight-chain saturated fatty acid which occurs naturally as esters of the oil of pelargonium.
Nonanoic acid has antifungal properties, and is also used as a herbicide as well as in the preparation of plasticisers and lacquers.
Nonanoic acid has a role as an antifeedant, a plant metabolite, a Daphnia magna metabolite and an algal metabolite.
Nonanoic acid is a straight-chain saturated fatty acid and a medium-chain fatty acid. It is a conjugate acid of a nonanoate. Nonanoic acid derives from a hydride of a nonane.
Nonanoic acid (Pelargonic acid, Nonoic acid) is a naturally occurring fatty acid found in both vegetable and animal fats.
Nonanoic acid (NNA) is a medium chain fatty acid, and is a naturally occurring carboxylic acid with a carbon chain length of nine.
Nonanoic acid is used in agricultural and veterinary (AgVet) chemical products as an herbicide, and may have other uses in therapeutic goods or fragrances.
Nonanoic acid has been used in a range of agricultural chemicals as an herbicide, both in combination with other actives (particularly glyphosate), but also as a stand-alone active constituent.
Commercial products are available with high concentrations of Nonanoic acid. Nonanoic acid is available as products for use in the home garden, both in ready to use formulations and also as concentrated formulations which require dilution prior to use.
Pelargonic acid, also known as nonanoic acid or pelargon, belongs to the class of organic compounds known as medium-chain fatty acids.
These are fatty acids with an aliphatic tail that contains between 4 and 12 carbon atoms.
Pelargonic acid is an oily liquid with an unpleasant, rancid odor.
It is a very hydrophobic molecule, practically insoluble in water but very soluble in organic solvents.
The biosynthesis of fatty acid occurs through the acetate pathway and the process is catalyzed by the Fatty Acid Synthase (FAS) enzymes.
Structurally, FAS varies significantly across different organisms but essentially, they all perform the same task using the same mechanisms.
Nonanoic acid is also used in the preparation of plasticizers and lacquers. Synthetic esters of nonanoic acid, such as methyl nonanoate, are used as flavorings.
The derivative 4-nonanoylmorpholine is an ingredient in some pepper sprays. The ammonium salt of nonanoic acid, ammonium nonanoate, is an herbicide.
It is commonly used in conjunction with glyphosate, a non-selective herbicide, to control weeds in turfgrass.
Pelargonic acid is a clear to yellowish oily liquid. It is insoluble in water but soluble in ether, alcohol and organic solvents.
The molecules of most natural fatty acids have an even number of carbon chains due to the linkage together by ester units.
Analogous compounds of odd numbers carbon chain fatty acids are supplemented synthetically.
Pelargonic acid, C-9 odd numbers carbon chain fatty acid, is relatively high cost fatty acid.
Pelargonic acid can be prepared by ozonolysis which uses ozone is to cleave the alkene bonds.
Example of ozonolysis in commerce is the production of odd carbon number carboxylic acids such as azelaic acid and pelargonic acid and simple carboxylic acids such as formic acid and oxalic acid.
Pelargonic acid forms esters with alcohols to be used as plasticizers and lubricating oils.
It is used in modifying alkyd resins to prevent discolor and to keep flexibility and resistance to aging since saturated pelargonic acid will not be oxidized.
Metallic soaps (barium and cadmium) and other inorganic salts used as a stabilizer.
It is also used as a chemical intermediate for synthetic flavors, cosmetics, pharmaceuticals and corrosion inhibitors.
It is known that C8 - C12 straight and saturated chain fatty acids are capable of removing the waxy cuticle of the broadleaf or weed, resulting in causing the tissue death. T
hey are used as active ingredient of environment friendly and quick effect herbicides. Pelargonic acid is the strongest one.
Nonanoic acid may be used to treat seizures (PMID 23177536).
Other names: n-Nonanoic acid; n-Nonoic acid; n-Nonylic acid; Nonoic acid; Nonylic acid; Pelargic acid; Pelargonic acid; 1-Octanecarboxylic acid; Cirrasol 185a; Emfac 1202; Hexacid C-9; Pelargon; Emery 1203; 1-Nonanoic acid; NSC 62787; n-Pelargonic acid; Emery 1202 (Salt/Mix)
IUPAC Name: nonanoic acid
Synonyms:
1-nonanoic acid
1-octanecarboxylic acid
CH3‒[CH2]7‒COOH IUPAC
n-nonanoic acid
n-nonanoic acid
Nonanoate
Nonanoic acid
Nonansäure Deutsch
nonoic acid
nonylic acid
pelargic acid
pelargon
Pelargonic acid
Pelargonsäure Deutsch
pergonic acid
nonanoic acid has parent hydride nonane
nonanoic acid has role Daphnia magna metabolite
nonanoic acid has role algal metabolite
nonanoic acid has role antifeedant
nonanoic acid has role plant metabolite
nonanoic acid is a medium-chain fatty acid
nonanoic acid is a straight-chain saturated fatty acid
nonanoic acid is conjugate acid of nonanoate
SYNONYMS :
NONANOIC ACID
Pelargonic acid
112-05-0
n-Nonanoic acid
Nonoic acid
Nonylic acid
Pelargic acid
n-Nonylic acid
n-Nonoic acid
1-Octanecarboxylic acid
Pelargon
Cirrasol 185A
Hexacid C-9
Emfac 1202
1-nonanoic acid
Fatty acids, C6-12
Fatty acids, C8-10
Nonansaeure
Pelargonsaeure
pergonic acid
MFCD00004433
nonoate
NSC 62787
UNII-97SEH7577T
68937-75-7
CH3-[CH2]7-COOH
CHEBI:29019
97SEH7577T
pergonate
n-nonanoate
1-nonanoate
C9:0
octan-1 carboxylic acid
1-octanecarboxylate
n-Nonanoic acid, 97%
DSSTox_CID_1641
DSSTox_RID_76255
DSSTox_GSID_21641
Pelargon [Russian]
1-Octanecarboxyic acid
CAS-112-05-0
FEMA No. 2784
HSDB 5554
EINECS 203-931-2
EPA Pesticide Chemical Code 217500
BRN 1752351
n-Pelargonate
AI3-04164
n-Nonylate
Perlargonic acid
n-Nonoate
n-pelargonic acid
KNA
EINECS 273-086-2
Nonanoic Acid Anion
Acid C9
Caprylic-Capric Acid
Nonanoic acid, 96%
3sz1
Emery's L-114
Pelargonic Acid 1202
Emery 1202
Emery 1203
octane-1-carboxylic acid
Preparation, occurrence, and uses
Pelargonic acid occurs naturally as esters in the oil of pelargonium.
Together with azelaic acid, it is produced industrially by ozonolysis of oleic acid.
H17C8CH=CHC7H14CO2H + 4O → HO2CC7H14CO2H + H17C8CO2H
Synthetic esters of pelargonic acid, such as methyl pelargonate, are used as flavorings.
Pelargonic acid is also used in the preparation of plasticizers and lacquers.
The derivative 4-nonanoylmorpholine is an ingredient in some pepper sprays.
The ammonium salt of pelargonic acid, ammonium pelargonate, is an herbicide.
It is commonly used in conjunction with glyphosate, a non-selective herbicide, for a quick burn-down effect in the control of weeds in turfgrass.
Pharmacological effects
Pelargonic acid may be more potent than valproic acid in treating seizures.
Moreover, in contrast to valproic acid, pelargonic acid exhibited no effect on HDAC inhibition, suggesting that it is unlikely to show HDAC inhibition-related teratogenicity.
IUPAC name: Nonanoic acid
Other names: Nonoic acid; Nonylic acid;
1-Octanecarboxylic acid;
C9:0 (Lipid numbers)
Identifiers
CAS Number: 112-05-0
EC Number: 203-931-2
Properties
Chemical formula: C9H18O2
Molar mass: 158.241 g·mol−1
Appearance: Clear to yellowish oily liquid
Density: 0.900 g/cm3
Melting point: 12.5 °C (54.5 °F; 285.6 K)
Boiling point: 254 °C (489 °F; 527 K)
Critical point (T, P): 439 °C (712 K), 2.35 MPa
Solubility in water: 0.3 g/L
Acidity (pKa): 4.96
1.055 at 2.06 to 2.63 K (−271.09 to −270.52 °C; −455.96 to −454.94 °F)
1.53 at −191 °C (−311.8 °F; 82.1 K)
Refractive index (nD): 1.4322
Hazards
Main hazards: Corrosive (C)
R-phrases (outdated): R34
S-phrases (outdated): (S1/2) S26 S28 S36/37/39 S45
Flash point: 114 °C (237 °F; 387 K)
Autoignition temperature: 405 °C
Categories: Alkanoic acids
Herbicides
Pelargonic Acid
Pelargonic acid is found naturally in pelargoniums and is a highly effective fatty acid widely used in the treatment of unwanted plants.
How does Pelargonic Acid work?
Pelargonic acid destroys the cell walls of the leaves of the weed.
This results in the cells losing their structure and drying out within a short space of time, under normal conditions this will be visible within 1 day after treatment.
Only the green parts of the plant are affected by this action, the woody bark of the plant is unaffected as the cells are too stable and the active ingredient has no way of penetrating the surface.
Therefore the product can be used under hedges, trees and bushes without fear of destroying the whole area.
Uses
Pelargonic acid occurs naturally in many plants and animals.
Pelargonic acid is used to control the growth of weeds and as a blossom thinner for apple and pear trees.
Pelargonic acid is also used as a food additive; as an ingredient in solutions used to commercially peel fruits and vegetables.
Pelargonic acid is present in many plants.
Pelargonic acid is used as an herbicide to prevent growth of weeds both indoors and outdoors, and as a blossom thinner for apple and pear trees.
The U.S. Food and Drug Administration (FDA) has approved this substance for use in food.
No risks to humans or the environment are expected when pesticide products containing pelargonic acid are used according to the label directions.
I. Description of the Active Ingredient Pelargonic acid is a chemical substance that is found in almost all species of animals and plants.
Because it contains nine carbon atoms, it is also called nonanoic acid.
It is found at low levels in many of the common foods we eat.
It is readily broken down in the environment.
II. Use Sites, Target Pests, And Application Methods Pelargonic acid has two distinct uses related to plants: weed killer and blossom thinner.
[Note: The substance can also be used as a sanitizer, a use not addressed in this Fact Sheet.]
o Weed killer Growers spray pelargonic acid on food crops and other crops to protect them against weeds.
For food crops, pelargonic acid is allowed to be applied from planting time until 24 hours before harvest.
The pre-harvest restriction assures that little or no residue remains on the food.
The chemical also controls weeds at sites such as schools, golf courses, walkways, greenhouses, and various indoor sites.
o Blossom thinner Growers use pelargonic acid to thin blossoms, a procedure that increases the quality and yield of apples and other fruit trees.
Thinning the blossoms allows the trees to produce fruit every year instead of every other year.
III. Assessing Risks to Human Health Pelargonic acid occurs naturally in many plants, including food plants, so most people are regularly exposed to small amounts of this chemical.
The use of pelargonic acid as an herbicide or blossom thinner on food crops is not expected to increase human exposure or risk.
Furthermore, tests indicate that ingesting or inhaling pelargonic acid in small amounts has no known toxic effects.
Pelargonic acid is a skin and eye irritant, and product labels describe precautions that users should follow to prevent the products from getting in their eyes or on their skin.
THE USE OF PELARGONIC ACID AS A WEED MANAGEMENT TOOL
Steven Savage and Paul Zomer Mycogen Corporation, San Diego, California In 1995, the Mycogen Corporation introduced Scythe®, a burn-down herbicide containing 60% of the active ingredient, pelargonic acid.
Pelargonic acid is a naturally occurring, saturated, nine-carbon fatty acid (C9:0).
Pelargonic acid occurs widely in nature in products such as goat's milk, apples and grapes.
Commercially it is produced by the ozonolysis of oleic acid (C18:1) from beef tallow.
Pelargonic acid has very low mammalian toxicity (oral, inhalation), is not mutagenic, teratogenic or sensitizing.
It can cause eye and skin irritation and thus the formulated product carries a WARNING signal word (Category II).
It has a benign environmental profile. As a herbicide, pelargonic acid causes extremely rapid and non-selective burn-down of green tissues.
The rate of kill is related to temperature, but under all but the coolest conditions the treated plants begin to exhibit damage within 15-60 minutes and begin to collapse within 1-3 hours of the application.
Pelargonic acid is not systemic and is not translocated through woody tissues.
It is also active against mosses and other cryptograms. Pelargonic acid has no soil activity.
As with most burn-down herbicides, pelargonic acid does not prevent re-growth from protected buds or basal meristems.
Many annual herbaceous weeds can be killed completely while larger weeds, grasses and woody plants may re-grow.
There are many practical applications of the rapid burn-down activity of pelargonic acid.
It can be used for spot weeding, edging, lining, turf renewal, chemical pruning and suckering.
It is particularly useful as a directed spray for killing annual weeds in container-grown woody ornamentals, under greenhouse benches and in other places where systemic herbicides can cause unwanted damage.
If the spray of pelargonic acid does come in contact with some desired plants, the damage is strictly limited to those leaves which are actually sprayed.
Pelargonic acid should be applied in at least 75 gallons/acre of total spray volume as activity declines at lower gallonages.
Evidence from P31 NMR studies suggests that the mode of action of pelargonic acid is not based on direct damage to cell membranes.
Pelargonic acid moves through the cuticle and cell membranes and lowers the internal pH of the plant cells.
Over the next several minutes the pools of cellular ATP and Glucose-6-phosphate decline.
Only later is there evidence of membrane dysfunction which eventually leads to cell leakage, collapse and desiccation of the tissue.
This chain of cellular events appears to allow pelargonic acid to synergize the activity of certain systemic herbicides such as glyphosate.
In general, bum-down herbicides are antagonistic to the activity of systemic herbicides, but in a tank mix pelargonic acid has been shown to allow greater and more rapid uptake of glyphosate without interfering with translocation.
This type of synergy is completely distinct from the enhancement seen with various surfactants used as adjuvants or formulation components for glyphosate.
By using high volume applications of a tank mix it is possible to combine the rapid kill of pelargonic acid with the systemic action of glyphosate.
At low application volumes (e.g. 20-30 GPA), pelargonic acid still enhances glyphosate uptake and improves its overall performance, but there is no immediate burn of the treated foliage.
Scythe herbicide was registered for non-crop use in 1995 and a crop registration is expected in 1996.
This commercial formulation of pelargonic acid has a wide range of weed control applications both as a contact, non-selective agent and as a tank mixing partner with systemic herbicides such as glyphosate.
The Herbicidal Potential of Different Pelargonic Acid Products and Essential Oils against Several Important Weed Species
Ilias Travlos 1,* , Eleni Rapti 1 , Ioannis Gazoulis 1 , Panagiotis Kanatas 2 , Alexandros Tataridas 1 , Ioanna Kakabouki 1 and Panayiota Papastylianou 1 1
Laboratory of Agronomy, Department of Crop Science, Agricultural University of Athens, 75 Iera Odos str., 118 55 Athens, Greece;
Published: 30 October 2020
Abstract: There is growing consideration among farmers and researchers regarding the development of natural herbicides providing sufficient levels of weed control.
The aim of the present study was to compare the efficacy of four different pelargonic acid products, three essential oils and two natural products’ mixtures against L. rigidum Gaud., A. sterilis L. and G. aparine L. Regarding grass weeds, it was noticed at 7 days after treatment that PA3 treatment (pelargonic acid 3.102% w/v + maleic hydrazide 0.459% w/v) was the least efficient treatment against L. rigidum and A. sterilis. The mixture of lemongrass oil and pelargonic acid resulted in 77% lower dry weight for L. rigidum in comparison to the control. Biomass reduction reached the level of 90% as compared to the control in the case of manuka oil and the efficacy of manuka oil and pelargonic acid mixture was similar.
For sterile oat, weed biomass was recorded between 31% and 33% of the control for lemongrass oil, pine oil, PA1 (pelargonic acid 18.67% + maleic hydrazide 3%) and PA4 (pelargonic acid 18.67%) treatments. In addition, the mixture of manuka oil and pelargonic acid reduced weed biomass by 96% as compared to the control.
Regarding the broadleaf species G. aparine, PA4 and PA1 treatments provided a 96–97% dry weight reduction compared to the corresponding value recorded for the untreated plants.
PA2 (pelargonic acid 50% w/v) treatment and the mixture of manuka oil and pelargonic acid completely eliminated cleaver plants.
The observations made for weed dry weight on the species level were similar to those made regarding plant height values recorded for each species.
Further research is needed to study more natural substances and optimize the use of natural herbicides as well as natural herbicides’ mixtures in weed management strategies under different soil and climatic conditions. Keywords: bioherbicide; pelargonic acid; manuka oil; lemongrass oil; pine oil; grass weeds; broadleaf weeds 1.
Introduction Weeds are considered to be one of the major threats to agricultural production since they affect the crop production indirectly, by competing with the crop for natural resources, sheltering crop pests, reducing crop yields and quality, and subsequently increasing the cost of processing [1]. Chemical control remains the most common control practice for weed management. Unfortunately, this overreliance on herbicides has led to serious problems, such as the possible injury to non-target vegetation and crops, the existence of herbicide residues in the water and the soil and concerns for human health and safety [2–5].
Another major issue associated with the use of synthetic herbicide is Agronomy 2020, 10, 1687; doi:10.3390/agronomy10111687 www.mdpi.com/journal/agronomy Agronomy 2020, 10, 1687 2 of 13 the growing problem of herbicide resistance since many harmful weed species including Amaranthus, Conyza, Echinochloa, and Lolium spp. are notorious for their ability to rapidly evolve resistance to a wide range of herbicide sites of action.
The development of natural herbicides based on either organic acids or essential oils could decrease these negative impacts.
They are less persistent in comparison to synthetic herbicides, more environmentally friendly, and they also have different modes of action which can prevent the development of herbicide-resistant weed biotypes [7,8]. Organic acids, essential oils, crude botanical products and other natural substances derived from plant tissues can be used as bio-herbicides in terms of weed management in both organic and sustainable agriculture systems [9].
Such natural substances face several opponents among the European Commission members, since there are doubts regarding the registration processes of natural products due to the lack of relevant toxicological data for their use at commercial scale [10]. Although these concerns might exist, there is evidence that most essential oils and their main compounds are not necessarily genotoxic or harmful to human health [11]. Such natural herbicides are sometimes less hazardous for environmental and human health in comparison to the commercial synthetic herbicides.
In the case of pelargonic acid, toxicity tests on non-target organisms, such as birds, fish, and honeybees, revealed little or no toxicity.
The chemical decomposes rapidly in both land and water environments, so it does not accumulate.
To minimize drift and potential harm to non-target plants, users are required to take precautions such as avoiding windy days and using large spray droplets.
However, product labels describe precautions that users should follow to prevent the products from getting in their eyes or on their skin since the acid is a skin and eye irritant [13].
Pelargonic acid (PA) (CH3(CH2)7CO2H, n-nonanoic acid) is a saturated, nine-carbon fatty acid (C9:0) naturally occurring as esters in the essential oil of Pelargonium spp. And can be derived from the tissues of various plant species [14–16]. Pelargonic acid along with its salts and formulated with emulsifiers is used in terms of weed management as a nonselective herbicide suitable either for garden or professional uses worldwide [8,14].
They are applied as contact burndown herbicides, which attack cell membranes and then as a result, cell leakage is caused and followed by membrane acyl lipids breakdown .
The phytotoxic effects due to the application of pelargonic acid are visible in a very short time after spraying and the symptoms involve phytotoxicity for the plants and their cells, which rapidly begin to oxidize, and necrotic lesions are observed on the aerial parts of plants [18].
The potential use of pelargonic acid as a bioherbicide poses an attractive non-chemical weed control option which can be effectively integrated with other eco-friendly weed management strategies in important crops such as soybean [19]. Several commercial pelargonic acid-based natural herbicides include also maleic hydrazide (1,2-dihydro-3,6-pyridazinedione) which is a systemic plant growth regulator that has also been used as a herbicide since its introduction [20].
Maleic hydrazide (1, 2-dihydropyridazine-3, 6-dione), a hormone-like substance synthesized and first introduced to USA in 1949, with crystal structure and structural similarity to the pyrimidine base uracil [20–22].
After application to foliage, maleic hydrazide is translocated in the meristematic tissues, with mobility in both phloem and xylem.
Although its mode of action is not clear, it can be used effectively for sprout suppression on vegetable crops such as onions and carrots as well as for the control of troublesome parasitic weed species where synthetic herbicides are limited [24–26]. Essential oils derived from a variety of aromatic, biomass, invasive or food crop plants are also known to have potential as natural non-selective herbicides [9,27–29].
Similarly, with the case of pelargonic acid, the foliage of weeds burns down in a very short time after application, which is more effective against young plants than older ones [30].
Manuka oil is isolated from the leaves of Leptospermum scoparium J. R. Forst. and G. Forst. and is considered to be an acceptable product in terms of organic standards [9].
The active ingredient in this essential oil is leptospermone, a natural b-triketone, which targets the enzyme p-hydroxyphenylpyruvate dioxygenase (HPPD) such as the conventional synthetic herbicides mesotrione and sulcotrione [31–33]. Lemongrass essential oil, derived from either Cymbopogon citratus Stapf. or C. flexuosus D.C. containing up to 80% citral is also commercialized Agronomy 2020, 10, 1687 3 of 13 as an organic herbicide whose mode of action involves the disruption of polymerization of plant microtubules [34].
Lemongrass oil acts as a contact herbicide, and since the active ingredient does not translocate, only the portions of plants receiving the spray solution are affected.
Pine essential oil is also commercialized as a 10% aqueous emulsion for weed control as a natural herbicide.
It is derived from steam distillation of needles, twigs and cones of Pinus sylvestris L. and a wide range of other species belonging to Pinus spp. and includes terpene alcohols and saponified fatty acids. Monoterpenes such as a- and b-pinene can increase the concentration of malondialdehyde, proline and hydrogen peroxide, indicating lipid peroxidation and induction of oxidative stress in weeds [35,36].
The aim of the present study was to evaluate and compare the efficacy of four different pelargonic acid products, three essential oils and two mixtures (of a pelargonic acid product and two essential oils) against three target weed species, i.e., rigid ryegrass (Lolium rigidum Gaud.), sterile oat (Avena sterilis L.) and cleaver (Galium aparine L.).
2. Materials and Methods 2.1. Plant Material Collection and Seed Pretreatment Seeds of rigid ryegrass (L. rigidum), sterile oat (A. sterilis) and cleaver (G. aparine) were collected from winter wheat fields of the origins of Fthiotida, Viotia and Larisa, respectively, during June 2019 (Table 1).
In each field, panicles and seeds were collected from 20 plants and transferred to the Laboratory of Agronomy (Agricultural University of Athens).
Table 1. Weed species studied, origins and geographical positions where seed collection was carried out. Common Name Scientific Name Origin Position Rigid ryegrass Lolium rigidum Gaud. Fthiotida 39◦08007” N, 22◦24056” E Sterile oat Avena sterilis L. Viotia 38◦24041” N, 23◦00040” E Cleaver Galium aparine L. Larisa 39◦25051” N, 22◦45047” E Two experiments were conducted and repeated twice to evaluate and compare the efficacy of the different pelargonic acid products, essential oils and mixtures of natural herbicides against the three target weed species.
The collected seeds were air-dried, threshed, placed in paper bags, and stored at room temperature to be used in the subsequent experimental runs.
Different were the seed pretreatment processes carried out to release dormancy in the seeds of the grasses and in the seeds of cleaver.
To release dormancy in the seeds of rigid ryegrass and sterile oat, the seeds were individually nicked with 2 teeth tweezers and placed in Petri dishes on two sheets of Whatman No.1 paper filter disk (Whatman Ltd., Maidstone, England) saturated with 6 mL distilled water, in 10 November. The Petri dishes were kept at 2–4 ◦C (refrigerator) for a period of 7 days. After that, the non-dormant seeds were used for sowing during the first experimental run, carried out during 2019. About half of the total collected grass weed seeds had been stored at room temperature to be used in the second experimental run, carried out during 2020. For cleaver, the seeds were sown in rectangular pots (28 × 30 × 70 cm3 ) and buried into the soil at approximately 3–4 cm depth, in 17 June. The pots were kept outside under natural conditions for 3 months to break the dormancy in the cleaver seeds.
The seeds were carefully removed from the pots in 19 September.
Afterwards, they were air-dried, placed and stored in paper bags at room temperature until use either for the first or the second experimental run.
Approximately fifteen seeds of rigid ryegrass and sterile oat, and twenty seeds of cleaver were sown in separate pots (12 × 13 × 15 cm3 ) in 18 November 2019, during the experiments of the first run. Rigid ryegrass and sterile oat seeds were sown at 1 cm depth.
Cleaver seeds were also sown at 1 cm depth to achieve maximum seedling emergence.
Pots had been filled with a mix of herbicide–free soil from the experimental field of the Agricultural University of Athens and peat at the ratio of 1:1 (v/v).
The soil of the experimental field is clay loam (CL) with pH value of 7.29, whereas the contents of CaCO3 and organic matter were 15.99% and 2.37%, respectively.
Moreover, the concentrations of NO3 − Agronomy 2020, 10, 1687 4 of 13 P (Olsen) and Na+ were 104.3, 9.95 and 110 ppm, respectively.
When the weed seedlings of all the weed species reached the appropriate phenological stage for spraying, they were carefully thinned to twelve plants per pot.
All pots were watered as needed and placed outdoors. The pots were randomized every 5 days in order to achieve uniform growth conditions for all the plants.
Regarding the duration of the first experiment, it was conducted between 18 November and 28 December 2019.
Regarding the second experimental run, the pot experiments were established in 14 January 2020 and were conducted until 25 February 2020.
For the second experimental run, the same courses of action were carried out regarding seed pretreatment and experiment establishment as compared to the corresponding ones carried out for the run. Typical climatic conditions for Greece were observed during the experimental periods.
Maximum month temperatures for November, December, January and February were 21.3, 15.6, 9.2 and 11.3 ◦C, respectively.
Minimum month temperatures for the same months were 14.2, 9.2, 2.1 and 1.8 ◦C, respectively, whereas total heights of precipitation for these months were 120.4, 90.6, 16.4 and 12.0 mm, respectively. 2.2. Experimental Treatments Several pelargonic acid products along with essential oils with a potential herbicidal action have been used. In particular, PA1 (3Stunden Bio-Unkrautfrei, Bayer Garten, Germany) and PA2 (Beloukha Garden, Belchim Crop Protection NV/SA, Technologielaan 7, 1840 Londerzeel, Belgium) contained only pelargonic acid at concentrations shown in Table 2, while PA3 and PA4 (Finalsan Ultima, W. Neudorff GmbH KG, Emmerthal, Germany) contained pelargonic acid along with maleic hydrazide (Table 2). For PA1, PA2, PA3 and PA4 treatments, pelargonic acid was applied as a single treatment without being mixed. Regarding the treatments containing essential oil application, EO1 (Manuka oil, Leptospermum scoparium, Salvia, India), EO2 (Lemon grass oil, Cymbopogon citratus, Sheer Essence, India) and EO3 (Pine oil, Pinus sylvestris, Sheer Essence, India) were used at 5% concentration.
All of the essential oils were diluted with water before treatment to achieve a 5% concentration.
In fact, commercial essential oils must be applied at high concentrations, often 10% or more per volume [30].
In the present study, an intermediate concentration of 5% was selected to reduce the cost of essential oil application in order to evaluate whether sufficient weed control can be achieved with the application of such natural herbicides at lower concentrations, acceptable also by an economic aspect. All herbicide applications were carried out with a handy pressure sprayer equipped with a variable conical nozzle.
Spraying was carried out at 0.3 MPa pressure and the spraying angle was 80◦ .
The height between the conical nozzle and the soil level was 40 cm for all the experimental treatments.
The spray head was set to move over the plants at 1.5 km h−1 and the apparatus was calibrated to deliver the equivalent of 200 L ha−1 .
The treatments were applied in 20 December, 2019, for the two runs of the first year (in 16 February 2020, for the two runs of the second year) when plants had reached the phenological stage of 2–3 true leaves, corresponding to stage 12–13 of the BBCH scale for rigid ryegrass and sterile oat, and the phenological stage of 3–4 true leaves, corresponding to stage 13–14 of the BBCH scale for cleaver. The pots were placed outdoors, and the leaves of the weed plants were vertically oriented at the time of spraying.
The experimental treatments were carried out at a sunny day and air temperature during spraying was 16.1 ◦C, for the first year (13.4 ◦C for the second year).
Table 2. The experimental treatments (e.g., natural herbicides) applied in the current study.
Treatment Active Ingredient Content in (g/L) or (mL/L) Dose Rate (L/ha) Active Ingredient per Unit Area in (g/ha) or (mL/ha) Abbreviation Control - - - -
Pelargonic acid 18.67% 18.67 1 200 3734 3 PA1 Pelargonic acid 50% 50 1 200 10000 3 PA2 Pelargonic acid 3.102% + maleic hydrazide 0.459% 3.102 1 200 620.4 3 PA3 Pelargonic acid 18.67% + maleic hydrazide 3% 18.67 1 + 3 1 200 3734 3 + 600 3 PA4 Agronomy 2020, 10, 1687 5 of 13
Table 2. Cont. Treatment Active Ingredient Content in (g/L) or (mL/L) Dose Rate (L/ha) Active Ingredient per Unit Area in (g/ha) or (mL/ha) Abbreviation Manuka oil 5% 5 2 200 1000 4 EO1 Lemongrass oil 5% 5 2 200 1000 4 EO2 Pine oil 5% 5 2 200 1000 4 EO3 Pelargonic acid 18.67% + maleic hydrazide 3% + Manuka oil 5% 18.67 1 + 3 1 + 5 2 200 3734 3 + 600 3 + 1000 4 M1 Pelargonic acid 18.67% + maleic hydrazide 3% + Lemongrass oil 5% 18.67 1 + 3 1 + 5 2 200 3734 3 + 600 3 + 1000 4 M2 1 Data refer to the active ingredient contents of the four different pelargonic acid formulations. The active ingredients are expressed in g/L. 2
Data refer to the active ingredient contents of the three different essential oil formulations.
The active ingredients are expressed in mL/L. 3 Data refer to the amount of the active ingredient of the four different pelargonic acid formulations per unit area.
The amounts are expressed in g/ha. 4 Data refer to the amount of the active ingredient of the three different essential oil formulations.
The amounts are expressed in mL/ha.
2.3. Evaluation of the Efficacy of Each Natural Herbicide against Targeted Weeds To evaluate the efficacy of each natural herbicide against the targeted weed species, dry weight and plant height of four plants per pot were measured for each weed species at 1, 3 and 7 days after treatment (DAT).
For measuring dry weight, the selected plants were dried at 60 ◦C for 48 h and then the measurements of dry weight were carried out.
The scale to measure dry weight had an accuracy of three decimal places and plant height was measured to nearest cm.
Each one of the experiments started with twelve plants in each pot and four plants were removed from each pot at 1, 3 and 7 DAT.
The assessment period was not longer than 7 DAT because the current experiment was focused on evaluating the knockdown effect of the natural herbicides on each one of the studied weed species. No observations regarding necrosis levels or NDVI values were made since these will be the objects of future experimentation. 2.4. Statistical Analysis Both of the experiments were repeated twice per year.
All the experiments were conducted in a completely randomized design with four replicates and nine experimental treatments (PA1, PA2, PA3, PA4, EO1, EO2, EO3, M1 and M2).
Four replicate pots were used for the evaluation of the effects of the experimental treatments on each weed species.
For all the experiments, the weed dry weight as well as the plant height values which corresponded to each treatment were measured, for each weed species separately. These values were recorded at 1, 3 and 7 DAT, and expressed as percentages of the corresponding values recorded for the untreated control plants.
An analysis of variance (ANOVA) combined over years and runs was conducted for all data and differences between means were compared at the 5% level of significance using the Fisher’s Protected LSD test. The ANOVA indicated no significant treatment x year interactions, across the two experimental runs, for each one of the weed species studied. Thus, the means of plant dry weight and height, for each weed species, were averaged over the two years and the two experimental runs.
Afterwards, the pooled data were analyzed by ANOVA at a ≤5% probability level using Statgraphics® Centurion XVI.
Fisher’s Protected LSD test was used to separate means regarding the effects of the application of the experimental treatments on plant dry weight and height for each one of the weed species studied.
3. Results 3.1. Effects of the Experimental Treatments on L. rigidum Dry Weight and Height In the first measurement carried out at 1 DAT, it was noticed that PA3 reduced dry weight of rigid ryegrass by 41% as compared to the control whereas biomass reduction was by 13% higher in the case of PA1.
The efficacy of manuka, lemongrass and pine essential oils was similar.
The mixture of manuka oil and pelargonic acid resulted in 63% lower rigid ryegrass dry weight than the value recorded for the untreated plants whereas similar was the efficacy of the mixture of lemongrass essential oil and pelargonic acid. In the second measurement, carried out at 3 DAT, it was revealed that PA3 resulted in Agronomy 2020, 10, 1687 6 of 13 48% lower fresh weight compared to the untreated control.
Rigid ryegrass dry weight was recorded at 34% and 37% of control when PA4 and EO3 treatments were applied, respectively.
Manuka oil provided the highest efficacy of all the experimental treatments against rigid ryegrass.
In the final measurement, carried out at 7 DAT, a 47% biomass reduction was recorded for PA3 as compared to the control.
Increased was the efficacy of PA2 and pine oil application since rigid ryegrass dry weight was recorded at 30% and 33% of control.
The mixture of lemongrass oil and pelargonic acid resulted in 77% lower dry weight in comparison to the value recorded for the control.
Biomass reduction reached the level of 90% as compared to the control in the case of manuka oil and similar was the efficacy of manuka oil and pelargonic acid mixture (Table 3).
Table 3. Dry weight and height of L. rigidum plants as affected by the application of the natural herbicides at 1, 3 and 7 days after treatment (DAT).
Dry weight and height values of L. rigidum plants was expressed as % of control.
Dry Weight (%) of Control Height (%) of Control Treatment 1 DAT 3 DAT 7 DAT 1 DAT 3 DAT 7 DAT PA1 46 b 42 ab 41 b 44 cb 43 b 40 ab PA2 34 d 29 cde 30 cd 38 bcd 27 def 28 cd PA3 59 a 52 a 53 a 63 a 54 a 51 a PA4 41 bcd 37 bcd 37 b 42 bcd 33 cde 35 bc EO1 41 bcd 27 de 10 e 45 b 28 cdef 8 e EO2 42 bc 39 bc 40 b 40 bcd 36 bc 38 bc EO3 38 cd 34 bcd 33 cd 37 de 35 bcd 36 bc M1 37 cd 22 e 6 e 36 e 24 f 7 e M2 36 cd 29 cde 23 d 40 bcd 26 ef 21 d LSD (0.05) 8 10 11 7 8 11 p value ** ** *** *** *** ** Different letters in the same column for L. rigidum dry weight and height, separately, indicate the significant differences between the means for each treatment at a = 5% significance level. **, *** = significant at 0.05, 0.01 and 0.001, respectively.
At 1 DAT, height of rigid ryegrass was recorded at 63% of the untreated control when PA3 was applied.
Lemongrass essential oil (EO2), PA2 and PA4 treatments resulted in 58–62% lower height as compared to the control.
The efficacy of the manuka oil and pelargonic acid mixture as well as the efficacy of pine oil was similar and slightly increased in comparison to the three treatments mentioned above.
In the second measurement carried out at 3 DAT, rigid ryegrass height was recorded at 43% of control in the case of PA1 whereas the adoption of PA2, PA4 and EO1 resulted in 67–73% in comparison to the control.
Similar was the efficacy of the two mixtures used since height reduction reached the level of 74–76% as compared to the value recorded for the untreated plants and these two treatments were the most efficient against rigid ryegrass. In the final measurement carried out at 7 DAT, the efficacy of PA3 was similar to the two previous measurements whereas the application of lemongrass and pine oil resulted in 62–64% lower plant height as compared to the control. In addition, PA2 was even more effective since plant height was recorded at 28% of control in the case of this treatment.
Manuka oil, as well as its mixture with pelargonic acid, were by far the most effective treatments since rigid ryegrass plant height was reduced by 92–93% (Table 3).
3.2. Effects of the Experimental Treatments on A. sterilis Dry Weight and Height Regarding sterile oat, at 1 DAT it was observed that PA3 reduced dry weight by 52% as compared to the control. The efficacy of PA2 treatment was significantly higher than PA3. Essential oils derived from manuka, lemongrass and pine showed similar efficacy.
The mixture of manuka oil and pelargonic acid (M1) was by approximately 6% more effective than the mixture of lemongrass oil and pelargonic acid (M2).
At 3 DAT, it was noticed that sterile oat dry weight was recorded at 44% of control when PA3 treatment was applied while the corresponding value recorded under pine oil application was Agronomy 2020, 10, 1687 7 of 13 recorded at 35% of control.
PA1 and PA4 treatments were more effective than PA3 treatment whereas lemongrass and manuka oils were characterized by similar efficacy.
The most effective treatment was the mixture of manuka oil and pelargonic acid given that its application reduced dry weight by 82% as compared to the control. The results of the measurement carried out at 7 DAT clarified that PA3 was the least efficient treatment against sterile oat since weed biomass was recorded at 41% of control whereas the corresponding values recorded for PA4, PA1, EO2 and EO3 treatments ranged between 31 and 33% of control. The efficacy of the lemongrass oil and pelargonic acid mixture was significantly higher.
Manuka oil resulted in a biomass reduction higher than 90% whereas the manuka oil and pelargonic acid mixture reduced weed biomass by 96% as compared to the value recorded for the untreated plants (Table 4). Table 4. Dry weight and height of A. sterilis plants as affected by the application of the natural herbicides at 1, 3 and 7 days after treatment (DAT). Dry weight and height values of A. sterilis plants was expressed as % of control. Dry Weight (%) of Control Height (%) of Control Treatment 1 DAT 3 DAT 1 DAT 3 DAT 1 DAT 3 DAT PA1 36 bcd 33 bc 33 ab 38 bc 36 b 35 ab PA2 27 e 24 de 23 bc 29 c 27 cde 24 cd PA3 48 a 44 a 41 a 53 a 46 a 42 a PA4 33 cde 30 bcd 31 ab 36 bc 33 bc 32 bc EO1 42 ab 28 bcd 7 de 44 ab 31 bcd 12 ef EO2 36 bcd 31 bcd 32 ab 37 bc 34 bc 34 ab EO3 39 bc 35 b 32 ab 42 b 37 b 35 ab M1 28 de 18 e 4 e 30 c 20 e 8 f M2 34 bcde 25 cde 17 cd 36 bc 25 de 19 de LSD (0.05) 9 8 11 9 7 9 p value * ** *** * ** *** Different letters in the same column for A. sterilis dry weight and height, separately, indicate the significant differences between the means for each treatment at a = 5% significance level. *, **, *** = significant at 0.05, 0.01 and 0.001, respectively.
Sterile oat height was recorded at 53% of control when PA3 was applied as it was observed at 1 DAT.
Sterile oat height ranged between 36% and 38% of control for PA4 and PA1 while almost the same plant height reduction was attributed to lemongrass essential oil application.
Height reduction was estimated at 30% as compared to the value recorded for the untreated plants in the case of manuka oil and pelargonic acid mixture.
This mixture was also approximately 6% more effective than the lemongrass oil and pelargonic acid mixture.
At 3 DAT, PA3 remained the least effective of all the studied treatments given that its efficacy was lower than the corresponding of EO3, PA1 and PA4 treatments.
The plant height values observed when manuka and lemongrass essential oils were applied were similar.
PA2 application resulted in 73% lower sterile oat height as compared to the control.
The efficacy of lemongrass oil and pelargonic acid mixture was similar, whereas mixing manuka oil and pelargonic acid was the most effective treatment of all against sterile oat.
The final measurement carried out at 7 DAT confirmed that PA3 was the least effective treatment of all, while lemongrass and pine essential oils were more efficient than PA3 treatment. Mixing lemongrass oil with pelargonic acid was more effective than the treatments mentioned above.
Manuka oil application was even more effective whereas its mixture with pelargonic acid resulted in the greatest plant height reduction which was recorded at 92% as compared to the control (Table 4). 3.3. Effects of the Experimental Treatments on G. aparine Dry Weight and Height In general, all the experimental treatments were more effective against cleaver than against the grass weeds studied. In particular, manuka and lemongrass essential oils provided a 67–70% biomass reduction in comparison to the control whereas biomass reduction for the two mixtures ranged between Agronomy 2020, 10, 1687 8 of 13 76% and 78% in comparison to the control as observed in the measurement carried out 24 h after treatment. The efficacy of all the pelargonic acid formulations was remarkable. At 3 DAT, it was observed that pine oil was 7% and 11% more effective than manuka and lemongrass essential oils, respectively, and the efficacy of the two mixtures was similar. PA3 treatment reduced weed biomass by 90%, whereas the application of PA2 treatment almost eliminated cleaver plants.
At 7 DAT, the efficacy of lemongrass and pine oils was similar, whereas manuka oil was characterized by increased efficacy (up to 92%).
PA4 and PA1 treatments resulted in a 96–97% dry weight reduction than the corresponding value recorded for the untreated plants. Weed dry weight was recorded at 6% of control in the case of lemongrass oil and pelargonic acid mixture whereas PA2 and M1 treatments completely eliminated cleaver plants (Table 5).
Table 5. Dry weight and height of G. aparine plants as affected by the application of the natural herbicides at 1, 3 and 7 days after treatment (DAT).
Dry weight and height values of G. aparine plants is expressed as % of control.
Dry Weight (%) of Control Height (%) of Control Treatment 1 DAT 3 DAT 1 DAT 3 DAT 1 DAT 3 DAT PA1 12 def 5 cd 4 d 14 def 6 cd 6 cd PA2 5 f 2 d 0 d 8 f 4 d 0 d PA3 17 cde 10 bc 8 bc 20 cde 12 bc 11 bc PA4 10 ef 5 cd 3 d 13 ef 6 cd 5 cd EO1 33 a 23 a 8 bc 36 a 27 a 11 bc EO2 30 ab 27 a 25 a 33 ab 29 a 27 a EO3 19 cd 16 b 14 b 21 cd 19 b 18 b M1 22 c 12 b 0 d 25 c 13 bc 0 d M2 24 bc 15 b 6 bc 26 bc 16 b 8 cd LSD (0.05) 8 6 9 8 7 9 p value *** *** ** *** *** ** Different letters in the same column for G. aparine dry weight and height, separately, indicate the significant differences between the means for each treatment at a = 5% significance level. **, *** = significant at 0.05, 0.01 and 0.001, respectively. Cleaver height was by 64 and 67% lower compared to the control when manuka and lemongrass oils were applied, respectively, as noticed at 1 DAT. The efficacy of manuka oil and pelargonic acid were by 11% higher than the corresponding value of manuka oil alone and even higher was the efficacy of PA4 and PA1. PA2 treatment was the most effective of all the treatments studied, since its application reduced weed height by approximately 92% as compared to the control.
The results of the second measurement revealed that cleaver height was recorded at 27% and 29% of control when manuka and lemongrass essential oils were applied, respectively.
The mixture of lemongrass oil and pelargonic acid was characterized by similar efficacy to pine oil whereas PA3 treatment reduced plant height by almost 88% as compared to the control.
At 7 DAT, it was noticed that lemongrass oil application was the least effective treatment against cleaver whereas pine oil was by 9% more effective. Cleaver height was only recorded at 5%, 6% and 8% of control when PA4, PA1 and M2 treatments were applied, while either manuka oil and pelargonic acid mixture or PA2 treatment completely eliminated cleaver plants (Table 5). 4. Discussion The results of the current study revealed the different efficacy of the four pelargonic acid products against the different weed species.
In most cases, broadleaf weeds like cleaver were more susceptible than grass species, while the formulations of increased pelargonic acid concentration (e.g., PA2) were significantly more effective. Our findings are in contrast with the corresponding of Muñoz et al. [8] who noticed that all the pelargonic acid-based herbicides managed to completely eliminate Avena fatua (L.) plants at 3 DAT whereas there were no significant differences regarding the efficacy of the different Agronomy 2020, 10, 1687 9 of 13 pelargonic acid formulations. The insufficient control of rigid ryegrass and sterile oat when the low-concentration formulation of pelargonic acid was applied is in agreement with the findings of a previous study in which the application of pelargonic acid at the concentration of 2% (v/v) provided only 20% total weed control [14]. However, the same authors noticed that the same treatment controlled broadleaf weeds such as velvetleaf (Abutilon theophrastii Medic.) by only 31%. In our study, cleaver was adequately controlled by the majority of the pelargonic acid-based treatments even 24 h after treatment.
Moreover, it was noticed that at 7 DAT, all the treatments did reduce cleaver dry biomass and plant height sufficiently.
The possible effects of climatic conditions on the efficacy and the overall results is something that should be further studied.
In our case, although weather conditions before and at spraying seemed favorable for the pot experiments, pelargonic acid products did not show remarkable efficacy against the two grass weed species. This outcome might be attributed to the air temperature at spraying time. The hypothesis of Krauss et al. [37] regarding the impact of weather conditions on the efficacy of pelargonic acid products was similar.
In any case, this is an objective that should be systematically evaluated in future studies.
In addition, there is evidence that various weed species can develop new shoots and recover after pelargonic acid application.
Hence, another objective for a future experiment would be to find out the level of weed regrowth that emerges over a longer term than 7 DAT for a wider range of weed species.
In fact, the natural substances are not translocated systemically in the plants and they cannot provide long-term weed control for most species.
However, it has already been reported that sufficient weed control might be achieved with repeated treatments.
Moreover, it was obvious that the different weed species’ responses to the application of the natural herbicides showed variability.
This emphasizes the importance of further multifactor experiments towards the comparison of the effects of such experimental treatments between numerous weed species.
The efficacy of pelargonic acid-based herbicides under real field conditions is an unexplored area of great interest.
There are not many studies evaluating the level of weed control in the field and defining the crops that can be favored by the adoption of such weed control practices.
However, there were interesting results in a more recent study carried out in Greece by Kanatas et al. in which pelargonic acid along with maleic hydrazide was applied for non-selective weed control before sowing soybean crop in a stale seedbed. In particular, it was revealed that stale seedbed combined with pelargonic acid application reduced annual weeds’ density by 95% as compared to normal seedbed, indicating that such pelargonic acid-based herbicides can be equally effective to glyphosate against annual weeds in a stale seedbed where a crop is about to be established and reap the benefits of pre-sowing weed elimination [19].
On one hand, it seems that integrated weed management strategies, including cultural practices such as the stale seedbed preparation, could maximize the herbicidal potential of pelargonic acid under real field conditions.
Consequently, the level of weed control as assured by pelargonic acid-based herbicides could be sufficient if a vigorous and competitive crop is about to be sown.
It has been reported recently in Greece that the competitiveness of barley (Hordeum vulgare L.) against troublesome weeds such as rigid ryegrass of sterile oat can be promoted if such organic weed control practices are applied before crop sowing [40].
On the other hand, after the nonanoic acid application, there was no weed cover reduction at one and two days after treatment in both experimental sites as well as repetitions in the field experiments of Martelloni et al. , where a treatment similar to PA-4 treatment was applied for weed control.
The explanation suggested for this outcome was that weeds were in unsuitable growth stage for the natural herbicide to have an effect.
Previous research has reported that nonanoic acid needs to be applied to very young or small plants for acceptable weed control, and repeated applications are suggested .
However, in the current experiment, it was observed that increasing pelargonic acid concentration in a natural herbicide product can result in more efficient control for grasses and barely elimination of broadleaves.
This finding is in agreement with the ones reported by Rowley et al., who observed an intermediate reduction in weed ground coverage, density, and dry weed biomass due to the higher rate of nonanoic acid used (39 L a.i. ha−1 ). Other authors found an intermediate reduction in Japanese stiltgrass (Microstegium vimineum Trin.)
Agronomy 2020, 10, 1687 10 of 13 ground coverage as compared to their control treatment due to the pelargonic acid application at a rate of 11.8 kg a.i. ha−1 and 5% (v/v) concentration [44]. Concerning the potential role of maleic hydrazide, this was not statistically significant in the present study, probably due to the measurements being only for 7 days and not on a long-term basis.
However, the use of products containing pelargonic acid along with maleic hydrazide is a promising tactic.
An explanation might be given by the fact that maleic hydrazide has systemic activity and can be translocated in the meristematic tissues, with mobility in both phloem and xylem.
Although its mode of action is not totally clear, it can be used effectively for the control of troublesome parasitic weed species belonging to Orobanche spp..
This is quite important, given that a factor restricting the herbicidal potential of pelargonic acid is the absence of systemic activity, with maleic hydrazide reducing weed regrowth and ensuring a long-term control.
The findings of the present study also revealed that manuka oil is a possible solution for dealing with the challenge of increasing the systemic activity of natural herbicides.
Even without being mixed with pelargonic acid, manuka oil showed increased efficacy against all the weeds as compared to the other essential oils and pelargonic acid treatments. In the study of Dayan et al. [32], it was noticed that manuka oil and its main active ingredient, leptospermone, were stable in soil for up to 7 d and had half-lives of 18 and 15 days after treatment, respectively. Such findings indicate the systemic activity of manuka oil and also that it can be a useful tool addressing many the restricting factors related to the use of natural herbicides. Dayan et al. [32] also recorded 68%, 57%, 93%, 88%, 73% and 50% lower biomass for pigweed (Amaranthus retroflexus L.), velvetleaf, field bindweed (Convolvulus arvensis L.), hemp sesbania [Sesbania exaltata (Raf.) Rydb. ex A.W. Hill], large crabgrass (Digitaria sanguinalis L.) and barnyardgrass (Echinochloa crus-galli L. P. Beauv.) as compared to the control, respectively, when a mixture with lemongrass essential oil was mixed with manuka oil and applied to the targeted weed species mentioned above. Pine and lemongrass essential oils provided a biomass reduction for rigid ryegrass and sterile oat ranging between 60% and 70% whereas they were more effective against the broad leaf species G. aparine.
In the study of Young [45], pine oil controlled hairy vetch (Vicia villosa Roth), broadleaf filaree (Erodium botrys (Cav.) Bertol.), and hare barley (Hordeum murinum L.) at least 83%, but yellow starthistle (Centaurea solstitialis L.), soft brome (Bromus hordeaceus L.), control never surpassed the level of 85%.
In the greenhouse experiment of Poonpaiboonpipat et al. [46], it was noted that lemongrass essential oil at concentrations of 1.25%, 2.5%, 5% and 10% (v/v) was phytotoxic against barnyard grass, since leaf wilt symptoms were observed at just 6 h after treatment.
The same authors also noticed that chlorophyll a, b and carotenoid content decreased under increased concentrations of the essential oil, indicating that lemongrass essential oil interferes with the weeds’ photosynthetic metabolism [46].
Although the herbicidal potential of such essential oils does exist, many studies have concluded that there are limitations since the essential oils act as contact herbicides with no systemic activity [9,30,32,45,46].
They generally disrupt the cuticular layer of the foliage, which results in the rapid desiccation or burn-down of young tissues.
However, lateral meristems tend to recover, and additional applications of essential oils are necessary to control regrowth.
Essential oils must be applied at high concentrations to convey 50 to 500 L of active ingredient per hectare [30].
The limitations of applying either lemongrass or pine essential oils for weed control are similar to those mainly observed in the case of pelargonic acid-based herbicides.
Manuka oil differs from other essential oils in that it contains large amounts of several natural b-triketones, including leptospermone, which enable this oil to have systemic activity [47].
One of the most important findings of the present study was the satisfactory control of all the targeted weed species in the case where the mixture of manuka oil and pelargonic acid was applied. This synergy resulted in improvement of overall weed control, compared to the cases in which pelargonic acid formulations, lemongrass and pine essential oils were used alone.
This is one of the key findings of this study, and provides vital information for improving weed control in terms of either organic or sustainable agriculture.
The findings of Coleman and Penner [14] were similar, finding that the addition of diammonium succinate and succinic acid improved the efficacy of a pelargonic acid formulation up to 200%, whereas l-Lactic acid and glycolic Agronomy 2020, 10, 1687 11 of 13 acid enhanced the efficacy of pelargonic acid formulations on velvetleaf and common lambsquarters (Chenopodium album L.) up to 138% even under real field conditions.
5. Conclusions To date, no studies have evaluated the herbicidal potential of several pelargonic acid products, essential oils and mixtures of natural herbicides against major weed species in Greece.
The findings of the present study revealed that selecting natural products with high concentrations of pelargonic acids can increase the control levels of grass weeds.
However, in the case of broadleaf weeds, it seems that the application of natural products might lead to sufficient weed control even when products of lower pelargonic acid concentration are applied. The results of the current study also validated that lemongrass and pine oil act as contact burn-down herbicides, whereas manuka oil showed a systemic activity.
The synergy between manuka oil and pelargonic acid is reported for the first time and is one of the key findings of the present study.
This unique essential oil might deal with the lack of systemic activity associated with pelargonic acid and further experiments are in progress by our team.
Further research is needed to evaluate more natural substances and combinations in order to optimize the use of natural herbicides as well as natural herbicides’ mixtures in weed management strategies in both organic and sustainable agriculture systems and also under different soil and climatic conditions.
Pelargonic Acid is a naturally-occurring saturated fatty acid with nine carbon atoms. The ammonium salt form of pelargonic acid is used as an herbicide.
Pelargonic Acid works by stripping the waxy cuticle of the plant, causing cell disruption, cell leakage, and death by desiccation.
Pelargonic acid is a C9 straight-chain saturated fatty acid which occurs naturally as esters of the oil of pelargonium.
Pelargonic acid has antifungal properties, and is also used as a herbicide as well as in the preparation of plasticisers and lacquers.
Pelargonic acid has a role as an antifeedant, a plant metabolite, a Daphnia magna metabolite and an algal metabolite.
Pelargonic acid is a straight-chain saturated fatty acid and a medium-chain fatty acid. It is a conjugate acid of a nonanoate. Nonanoic acid derives from a hydride of a nonane.
γ-nonanolactone has functional parent nonanoic acid
(8R)-8-hydroxynonanoic acid has functional parent nonanoic acid
(R)-2-hydroxynonanoic acid has functional parent nonanoic acid
1-nonanoyl-2-pentadecanoyl-sn-glycero-3-phosphocholine has functional parent nonanoic acid
1-octadecanoyl-2-nonanoyl-sn-glycero-3-phosphocholine has functional parent nonanoic acid
2-hydroxynonanoic acid has functional parent nonanoic acid
2-oxononanoic acid has functional parent nonanoic acid
7,8-diaminononanoic acid has functional parent nonanoic acid
8-amino-7-oxononanoic acid has functional parent nonanoic acid
9-(methylsulfinyl)nonamide has functional parent nonanoic acid
9-(methylsulfinyl)nonanoic acid has functional parent nonanoic acid
9-aminononanoic acid has functional parent nonanoic acid
9-hydroxynonanoic acid has functional parent nonanoic acid
9-oxononanoic acid has functional parent nonanoic acid
N-nonanoylglycine has functional parent nonanoic acid
ethyl nonanoate has functional parent nonanoic acid
hexadecafluorononanoic acid has functional parent nonanoic acid
methyl nonanoate has functional parent nonanoic acid
nonanal has functional parent nonanoic acid
nonanoyl-CoA has functional parent nonanoic acid
perfluorononanoic acid has functional parent nonanoic acid
trimethylsilyl nonanoate has functional parent nonanoic acid
nonanoate is conjugate base of nonanoic acid
nonanoyl group is substituent group from nonanoic acid
acid nonanoic (ro)
Acid nonanoic, acid pelargonic (ro)
acide nonanoique (fr)
Acide nonanoïque, acide pélargonique (fr)
acido nonanoico (it)
Acido nonanoico, acido pelargonico (it)
Aċidu nonanoiku, Aċidu pelargoniku (mt)
kwas nonanowy (pl)
Kwas nonanowy, kwas pelargonowy (pl)
kwas pelargonowy (pl)
Kyselina nonanová, kyselina pelargonová (cs)
kyselina nonánová (sk)
Kyselina nonánová (kyselina pelargónová) (sk)
Nonaanhape (et)
Nonaanhape, pelargoonhape (et)
Nonaanihappo (fi)
Nonaanihappo (pelargonihappo) (fi)
nonaanzuur (nl)
Nonaanzuur, pelar-goonzuur (nl)
nonano rūgštis (lt)
Nonano rūgštis, pelargono rūgštis (lt)
Nonanoic acid, Pelargonic acid (no)
nonanojska kislina (sl)
Nonanojska kislina, pelargonska kislina (sl)
nonanonska kiselina (hr)
nonanová kyselina (cs)
Nonanska kiselina, pelargonična kiselina (hr)
nonansyra (sv)
Nonansyra, pelargonsyra (sv)
nonansyre (da)
nonansyre (no)
Nonansyre og pelargonsyre (da)
Nonansäure (de)
Nonansäure, Pelargonsäure (de)
nonánsav (hu)
Nonánsav, pelargonsav (hu)
Nonānskābe (lv)
nonānskābe (lv)
ácido nonanoico (es)
Ácido nonanoico, ácido pelargónico (es)
ácido nonanóico (pt)
Ácido nonanóico, Ácido pelargónico (pt)
Εννεανικό οξύ (πελαργονικό οξύ) (el)
εννεανοϊκό οξύ (el)
нонанова киселина (bg)
Нонанова киселина, пеларгонова киселина (bg)
CAS names: Nonanoic acid
IUPAC names
Acid C9, Pelargonic acid
NONANOIC ACID
Nonanoic Acid
Nonanoic acid
nonanoic acid
nonanová kyselina
Nonansäure
Pelargonic acid
Pelargonic and realted fatty acids
Trade names
Acido Pelargónico
Pelargonic acid
Prifrac 2913
Prifrac 2914
Prifrac 2915
Synonyms
1-nonanoic acid
1752351 [Beilstein]
267-013-3 [EINECS]
506-25-2 [RN]
Acid C9
Acide nonanoïque [French] [ACD/IUPAC Name]
n-nonanoic acid
n-Nonylic acid
Nonanoic acid [ACD/Index Name] [ACD/IUPAC Name]
Nonansäure [German] [ACD/IUPAC Name]
n-Pelargonic acid
Pelargonic Acid
RA6650000
Pergonic acid
130348-94-6 [RN]
134646-27-8 [RN]
1-OCTANECARBOXYLIC ACID
4-02-00-01018 (Beilstein Handbook Reference) [Beilstein]
Cirrasol 185A
EINECS 203-931-2
EINECS 273-086-2
Emery 1203
Emery'S L-114
http://www.hmdb.ca/metabolites/HMDB0000847
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:29019
Jsp000917
KNA
KZH
MLS001066339
NCGC00164328-01
n-Nonanoic-9,9,9-d3 acid
n-Nonoic acid
Nonansaeure
noncarboxylic acid
nonoic acid
nonylic acid
Pelargic acid
pelargon
Pelargon [Russian]
Pelargon [Russian]
Pelargonic Acid 1202
Pelargonsaeure
SMR000112203
VS-08541
WLN: QV8
Synonym Source
1-Nonanoate
1-Nonanoic acid ChEBI
1-Octanecarboxylate
1-Octanecarboxylic acid
CH3-[CH2]7-COOH
Cirrasol 185a
Emery 1202
Emery'S L-114
Emfac 1202
FA(9:0)
Product name
Nonanoic acid (Pelargonic acid), Fatty acid
Description
Fatty acid.
Alternative names
Pelargonic acid
Biological description
Potent antifungal agent (IC50 = 50 μM against Trichophyton mentagrophytes). Inhibits spore germination and mycelial growth of pathogenic fungus. Active in vivo.
Nonanoic acid is now used relatively extensively as an herbicide in the home garden. A recent evaluation of an acute eye irritation study indicated moderate eye irritation following exposure to a product formulation containing 1.8% nonanoic acid.
Applications
Nonanoic acid is used in the preparation of plasticizers and lacquers. It is commonly used in conjunction with glyphosate, for a quick burn-down effect in the control of weeds in turfgrass.
Investigation of antimicrobial activities of nonanoic acid derivatives
January 2006Fresenius Environmental Bulletin 15(2):141-143
Abstract and Figures
In a search for promising antimicrobial compounds, seven derivatives of methyl-branched n-nonanoic acid (MNA) at positions 2, 3, 4, 5, 6, 7, and 8 have been synthesized, and antimicrobial activity is described. Anti-microbial activities were determined by using disk diffusion tests and expressed as MIC values for the n-nonanoic acid using the microdilution broth method in vitro against Bacillus subtilis, Mycobacterium smegmatis, Sarcina lutea, Escherichia coli, Salmonella typhimurium and Streptomyces nojiriensis for bacteria, and Candida utilis for fungi, and compared with Penicillin G and Polymyxin B. All compounds exhibit varied antimicrobial activity against Gram-positive bacteria, but remarkable inhibitory effects were observed against C. utilis and S. lutea in two compounds (2-MNA and 5-MNA). Interestingly, only 4-MNA, 7-MNA and 8-MNA possess activity against Streptomyces.
Synonyms
Pelargonic acid; 1-Octanecarboxylic acid; Cirrasol 185A; Cirrasol 185a; Emfac 1202; Hexacid C-9; Nonoic acid; Nonylic acid; Pelargic acid; Pelargon [Russian]; n-Nonanoic acid; n-Nonoic acid; n-Nonylic acid; [ChemIDplus]
Sources/Uses
Naturally occurs as an ester in oil of pelargonium; [Merck Index] Found in several essential oils; Used in lacquers, pharmaceuticals, plastics, and in esters for turbojet lubricants; Also used as a flavor and fragrance, flotation agent, gasoline additive, herbicide, blossom thinner for apple and pear trees, sanitizer, and to peel fruits and vegetables; [HSDB] Used to make peroxides and greases, as a catalyst for alkyd resins, in insect attractants, and as a topical bactericide and fungicide medication; [CHEMINFO]
Comments
Category of C7-C9 aliphatic aldehydes and carboxylic acids: Members and supporting chemicals demonstrate low acute toxicity by oral, dermal, and inhalation exposures; toxicity in repeated-dose studies only at relatively high levels; no evidence of reproductive toxicity, developmental toxicity, or mutagenicity; [EPA ChAMP: Hazard Characterization] Highly irritating; [Merck Index] A strong skin irritant; [Hawley] A skin and eye irritant; [HSDB] May cause permanent eye damage, including blindness; [CHEMINFO] Safe when used as a flavoring agent in food; [JECFA] A corrosive substance that can cause injury to the skin, eyes, and respiratory tract; [MSDSonline]
Use of nonanoic acid as an antimicrobial agent, in particular an antifungal agent
Abstract
The invention relates to the use of nonanoic acid as an antimicrobial, in particular antifungal, agent or additive, in particular in or for foods, such as dairy products or fruit juices.
A particular aspect of the invention comprises the use of nonanoic acid i a cheese coating.
The invention also relates to a cheese coating in which nonanoic acid has been incorporated as antifungal agent; a cheese that has been provided with such a coating; and a nonanoic acid-containing composition for applying such a coating.
The nonanoic acid is used in particular on or close to the surface of the food, or uniformly distributed through the food, in an amount of 10 - 10,000 ppm, in particular 100 - 1,000 ppm. The nonanoic acid can furthermore be used as an antimicrobial agent for treating substrates or surfaces, in particular substrates or surfaces that come into contact with foods; for protecting foods, cut flowers and bulbs during transport and/or during storage; in disinfectants and cleaning agents; to protect or treat wood; in cosmetics or skin care products; and in pharmaceutical compositions to prevent and treat fungal infections and yeast infections , such as Candida.
Use of nonanoic acid as an antimicrobial agent, in particular an antifungal agent
The present invention relates to the use of nonanoic acid as an antimicrobial agent, in particular an antifungal agent.
More particularly, the invention relates to the use of nonanoic acid as an antimicrobial agent, in particular an antifungal agent, in foods and in particular in dairy products such as cheese and products based on fruit, such as fruit juices.
The invention furthermore relates to foods which contain nonanoic acid as an antimicrobial agent.
Particular aspects of the invention lie in the use of nonanoic acid in (solutions or suspensions for) cheese coatings, in the nonanoic acid-containing cheese coatings thus obtained and in the cheeses coated with these nonanoic acid-containing coatings.
The use of the nonanoic acid in food products is known.
For instance, it is used as a synthetic flavouring in, for example, non-alcoholic drinks, ice cream, confectionery, gelatine, milk puddings and bakery products.
US Patent 2 154 449 describes the antifungal properties of C3 - CI2 carboxylic acids and salts thereof, in particular the incorporation of calcium propionate in bread dough in order to prevent the formation of mould on bread.
European Patent Application EP 0 244 144 A 1 teaches the addition of glyceryl fatty acid esters in combination with one or more C6.C,8 carboxylic acids as preservatives to, inter alia, food compositions.
International application WO 96/29895 describes a method for improving the shelf/storage life of perishable products by treating surfaces, equipment and materials, which come into contact with the products during the processing thereof, with an antimicrobial aromatic compound.
WO 96/29895 states that fatty acids, including nonanoic acid, can also be used in combination with the aromatic compound.
International application WO 92/19104 teaches the use of C7 - C20 carboxylic acids, including nonanoic acid, for controlling infections in plants caused by bacteria and moulds.
European Patent Application EP 0 022 289 relates to the incorporation of C3 - C, , carboxylic acids in polymers for the production of medical instruments, such as catheters.
European Patent Application EP 0 465 423 describes antimicrobial pharmaceutical preparations containing C4 - C,4 carboxylic acids.
US Patent 4 406 884 describes antimicrobial pharmaceutical preparations for topical use which contain C5 - C,2 carboxylic acids.
US Patent 3 931 413 teaches the treatment of plants with C6 - C,8 carboxylic acids to combat infections by moulds which overwinter in the buds of the plants.
Nonanoic acid is also used in some meat products to adjust the acidity.
For instance, US Patent 4 495 208 describes a dog or cat food with good storage/shelf life which has a high moisture content (Aw > 0.9 and a water content of 50 - 80 %) that contains 4 -15 % (m/m) fructose, 0.3 - 3.0 % (m/m) of an edible organic acid, sufficient inorganic acid to obtain a pH in the range of 3.5 - 5.8 and an antifungal agent.
The organic acid is preferably chosen from heptanoic acid, octanoic acid, nonanoic acid or a combination thereof.
In the animal feed according to US Patent 4 495 208 the edible organic acid is always present alongside a sugar (fructose) and an antifungal agent (antimycotic) known per se, such as sorbic acid and/or the salts thereof.
It is stated that the combination of these three constituents in the indicated amounts gives a synergistic bactericidal action.
US Patent 3 985 904 describes a food based on meat which has a high moisture content and is suitable for human consumption or as an animal feed.
This food has a moisture content of at least approximately 50 % (m m) and a water activity A,,, of at least approximately 0.90 and contains more than 50 % (m/m) of a ground, boiled, protein-like chicken, fish or meat material. 1 - 35 % (m m) of a gelatine-like filler based on starch, between 1.7 and 3.8 % of an edible, non-toxic acid and an effective amount of an antifungal agent.
The edible organic acid is incorporated in this food in an amount which is sufficient to bring the pH of the food to a value in the range from 3.9 to 5.5.
Although US-A 3 985 904 mentions various suitable edible acids in column 6, nonanoic acid is not explicitly mentioned here.
According to US-A 3 985 904, the antifungal agent is chosen from benzoates, propionates and sorbate salts.
EP-A 0 876 768 describes the use of fatty acid monoesters of polyglycerol to improve the storage/shelf life of foods.
Here the fatty acid radicals can be chosen from caproic acid, caprylic acid, lauric acid or myristic acid.
The use of nonanoic acid in herbicidal compositions for agricultural use is described, inter alia, in US Patents 5 098 467, 5 035 741, 5 106 410 and 5 975 4110. US Patents 4 820 438, 5 330 769 and 5 391 379 describe the use of nonanoic acid in soap and cleaning agents.
None of the above literature citations describes or suggests unambiguously that nonanoic acid can be safely incorporated in foods and/or can be used on foods in order to inhibit the growth of bacteria, moulds and yeasts. In particular, none of these literature citations teaches the dosage at which nonanoic acid can safely be used for this purpose.
Currently, natamycin is used as antifungal agent in cheese making.
This compound, which is also designated pimaricin or "antibiotic A5283" and is marketed under the trade names Delvocid® and Natamax® (inter alia), is a metabolic product of Streptomyces natalensis and S. chattanoogensis.
However, the use of natamycin has a number of disadvantages. For instance it is fairly expensive.
Moreover, it has been found that the mould Penicillium discolor is able to grow on (the surfaces of) cheeses treated with natamycin.
This is particularly disadvantageous in the cheese industry, since P. discolor is widespread in cheese warehouses.
It has now been found that nonanoic acid displays an antimicrobial action, in particular an antifungal action, especially when it is used in amounts which can suitably be incorporated in food products. More particularly, it has been found that nonanoic acid can advantageously be used as an antimicrobial agent, in particular antifungal (fungicidal) agent, in dairy products such as cheese and products based on fruit, such as fruit juices.
The antimicrobial action of nonanoic acid found according to the invention is partly surprising because it is known that some types of mould (such as Aspergillus niger, Synchephalastrum racemosus, Geotrichum candidum, Penicillium expansum, Rhizopus stolonifer and Mucor plombus) naturally produce nonanoic acid.
In addition, it has been found according to the invention that nonanoic acid is also able to inhibit the development of yeasts, which can likewise arise in cheese warehouses.
In a first aspect the invention therefore relates to the use of nonanoic acid (n-octane- 1 -carboxylic acid, pelargonic acid, n-nonylic acid) as an antimicrobial agent, in particular antifungal agent (additive) in or for foods and/or other products which have to be protected against perishing caused by microorganisms.
The invention also relates to the use of salts of nonanoic acid as an antimicrobial agent.
The invention further relates to foods which contain nonanoic acid as an antimicrobial agent, in particular antifungal agent.
The food can be any substance that is suitable for consumption by humans or animals, in particular for human consumption, and can be either a ready-to-eat food product or a constituent that can be incorporated in or processed to give a food product. The food or food product is in particular a product or substance that is susceptible to perishing caused by microorganisms, including bacteria, yeasts and in particular moulds (that is to say when no antimicrobial agent is added), such as, for example, a substance or product which will keep for between a few days and a few weeks (for example from 3 days to 3 weeks) under the customary conditions for storage of the product, such as a temperature in the range from room temperature (20 - 25 °C) down to refrigerator temperature (approximately 4 °C). However, the invention is not restricted to these.
In this context the nonanoic acid is used to inhibit microbial growth, in particular the formation of mould, and thus to extend the storage/shelf life.
For instance, microbial growth can be retarded by the use of nonanoic acid.
The degree of retardation will be dependent on, inter alia, the food, the nonanoic acid concentration, the conditions under which the food is stored (temperature, atmospheric humidity), the types of microorganisms to which the food is exposed and the degree of loading.
In the case of mould formation, the mould formation (i.e. the point in time at which the first growth of mould is discernible to the naked eye) will in general be delayed by at least one day, preferably at least 5 - 7 days, that is to say at the temperature at which foods are usually stored - usually room temperature (20 °C) or in the refrigerator (4 °C) - compared with the untreated food. For instance, in the case of cheese that was coated with a nonanoic acid-containing coating according to the invention the first discernible formation of mould was postponed from 60 to 67 days. In this context reference is made to Example 1 below, as well as the results given in Figure 1.
For the purposes of the invention, "inhibiting mould formation" and/or "antifungal" is preferably also understood to mean that the development of yeasts is (also) inhibited.
Moreover, it has been established according to the invention that nonanoic acid also has an antibacterial action, for example against bacteria which cause food to perish or otherwise reduce the quality thereof, and or against pathogens such as Listeria, Legionella, Salmonella and E.coli O157, Staphylococcus.
This inhibitory action of nonanoic acid on (the growth of) bacteria can also advantageously be employed in (the preparation of) fermented dairy products such as yoghurt.
This will be explained in more detail below. The food can be a solid, semi-solid or fluid food and can be a fermented or non- fermented food.
A few non-limiting examples of foods in which nonanoic acid can be used according to the invention as an antimicrobial agent, in particular antifungal agent, are: - ready-to-eat food products, including dough products such as pre-baked bread, noodles, pasta, soups and the like; fish and meat products such as sausage, and products based on vegetables or fruit, such as fruit juices and canned fruit or combinations of fruit (juices) with dairy products; flour; nuts and (dried) southern fruits; and also products such as pre-prepared meals, diet foods, complete foods and baby food; foods and constituents for further processing, such as mayonnaise, ketchup and similar sauces; jam, marmalade and similar fruit preparations; and the like. According to the invention nonanoic acid can also be used outside the food sector as an antimicrobial agent, in particular antifungal and/or antibacterial agent, and examples of this will be given below.
One example that is worthy of mention at this juncture is the use of nonanoic acid or a nonanoic acid-containing coating to improve the storage/shelf life of fruit such as oranges, lemons, grapefruit, apples, pears and also nuts and (dried) southern fruits, coffee, tea, tobacco and the like, in particular before or during transport and/or during long-term storage, for example in a warehouse or a fruit store (which may or may not be air- conditioned).
When used as an antifungal agent according to the invention, the nonanoic acid will be used in an amount effective for the inhibition of moulds, yeasts and bacteria, which as a rule will be between 1 and 10,000 mg nonanoic acid per kg food, in particular 10-1,000 mg nonanoic acid per kg food and more particularly 100-500 mg nonanoic acid per kg food.
Thus, for example, nonanoic acid can be used in yoghurt in an amount of approximately 200 milligram (mg) nonanoic acid per kilogram (kg) yoghurt.
The lower limit for the effective amount of nonanoic acid will preferably be chosen from the series 10, 25, 50 or 100 mg nonanoic acid per kg food, whilst the upper limit is preferably chosen from the series 10,000, 5,000, 2,500, or 1,000 mg nonanoic acid per kg food.
Preferably, these amounts are based on the water content of the food. Thus, in the case of a food having a water content of 80 %, 80 % of the abovementioned amounts of nonanoic acid can also be added per kg food. The precise amount of nonanoic acid will, however, be dependent on the intended food and the way in which the nonanoic acid is used in the food.
Thus, the nonanoic acid can be uniformly distributed throughout the entire food but, for example - especially in the case of solid or semi-solid foods - can also be present essentially only on or near the surface of the food, for example in the form of a nonanoic acid-containing antimicrobial, in particular antifungal, coating or surface layer, or as a result of treatment of the surface of the food with nonanoic acid. In these latter cases the concentration of nonanoic acid, based on the complete food, can be low (that is to say lower than the amounts indicated above), provided that sufficient nonanoic acid is present at or close to the surface in order to achieve the desired antimicrobial, in particular antifungal, action.
In general the presence of nonanoic acid in amounts of 10 - 10,000 ppm, in particular 100 - 2,000 ppm - i.e. locally or uniformly throughout the entire food - will be adequate to obtain the desired antimicrobial, in particular antifungal, action. The same concentrations of nonanoic acid - i.e. locally or uniformly throughout the entire food - will as a rule be sufficient to inhibit and/or to prevent the growth of yeast and/or of bacteria.
In a preferred aspect the food product is a dairy product, which in general is defined as a food based on milk or constituents of milk, in particular based on cows milk or constituents thereof. The dairy product is in particular a fermented dairy product that can be solid, semi- solid or fluid.
A few non-limiting examples are cheese, butter, cream, yoghurt or yoghurt products (for example yoghurt drinks, such as, for example, milk/fruit juice drinks), cottage cheese, kefir, milk puddings and the like.
The invention can also be employed in food products in which such dairy products have been incorporated/processed, such as sauces, pastries, desserts, foods (including complete food and baby food), snacks (for example containing cheese), meat products (such as ham in which proteins have been incorporated), powdered milk and coffee whiteners, and the like.
Use in cheese, and in particular in cheeses which have a low salt content (that is to say less than 4 %, in particular less than 3 %) and a high moisture content (that is to say 30 % or more, in particular 40 % or more) is to be particularly preferred. This can be carried out in particular by treating the surface of the cheese with nonanoic acid.
Thus, the invention can (also) be used with feta, cheese spread and similar products.
The fermented dairy product preferably has a pH of 3.5 to 5.5, for example in the range of 5.1 - 5.5 for cheese and of 3.9 - 4.4 for yoghurt.
Although it is not precluded that addition of nonanoic acid according to the invention makes some (usually minor) contribution to achieving this value, the final pH will as a rule be the result of the fermentation process and the buffer action possibly associated with this.
In another preferred embodiment the food product is a fruit juice or similar drink, such as, for example, products in which dairy products such as milk or yoghurt and fruit juices have been processed, which have a limited shelf-life.
The nonanoic acid can be used in a manner known per se for antimicrobial agents, in particular antifungal agents, that is to say by adding the nonanoic acid or a nonanoic acid- containing additive to the food or food product, or incorporating the nonanoic acid or a nonanoic acid-containing additive in the food or food product, during and/or after the preparation thereof. During this operation the nonanoic acid can be uniformly mixed or distributed through the food and/or used on the surface of the food, for example by spraying or brushing with nonanoic acid (for example in the form of an aqueous solution), by immersing (in particular cheese) in a solution of nonanoic acid or by applying a nonanoic acid-containing coating. For this operation it is possible to use, for example, an aqueous solution or suspension of nonanoic acid or another nonanoic acid-containing, preferably liquid, mixture, which contains 100 - 5,000 ppm, in particular 200 to 3,000 ppm nonanoic acid and which furthermore can contain all constituents known per se for solutions for applying a cheese coating, such as (the constituents of) synthetic coatings known per se (for example based on copolymers) and/or coatings based on foodstuffs.
For instance - in a 140 gram coating for a 12.8 kg cheese - the nonanoic acid concentration in the coating can be 5,000 ppm (which corresponds to 49.2 mg nonanoic acid per kg cheese), 1,000 ppm (which corresponds to 9.8 mg/kg cheese) or 100 ppm (which corresponds to 0.98 mg/kg cheese).
The nonanoic acid-containing cheese coating thus obtained, the cheeses which have been provided with such nonanoic acid-containing cheese coatings and the nonanoic acid- containing solutions which are used in this operation form further aspects of the invention.
In this context a further advantage of nonanoic acid is that it is also able to counteract and/or prevent too extensive development of the surface flora on the cheese (coating) - which can lead to the cheese rind being adversely affected - (this is in contrast to natamycin, that essentially is not able to exert any influence on bacterial growth).
As a rule the nonanoic acid will be used to replace the one or more antimicrobial, in particular antifungal, additives already used in a food known per se.
In addition, the nonanoic acid can advantageously be used in those foods for which the known antimicrobial agents are unsuitable or less suitable.
For such applications the use of nonanoic acid can form an alternative to the sterilisation treatments and/or similar antimicrobial treatment (that is to say other than the use of an antimicrobial additive) which are otherwise required.
Usually a single treatment of the food with nonanoic acid - such as the application of a nonanoic acid-containing coating - will be sufficient to obtain the desired antimicrobial action. However, repeated treatment of the food with nonanoic acid is not precluded.
According to the invention nonanoic acid is used in particular to replace natamycin, in particular in applications in the dairy and cheese industries. In this regard reference is made, for example, to the applications of natamycin which are described by J. Stark in E>e Ware(n) Chemicus, 27 (1997), 173-176.
According to the invention nonanoic acid is highly preferentially compatible with the food, that is to say the use of nonanoic acid according to the invention has no adverse effect on the flavour, odour, consistency, pH or other desired characteristics of the food, at least not during the time that the food has to be or can be kept or stored prior to end use or consumption.
As a rule this means that the food must be acid-resistant to a certain extent, that is to say at least must be able to withstand the pH that is obtained by the use of the nonanoic acid in the abovementioned amounts. In the event of possible problems with the compatibility, the use of a separate nonanoic acid-containing coating can offer a solution.
The food can furthermore contain all other additives known per se for the food, provided that these are compatible with nonanoic acid and do not adversely affect the antimicrobial action thereof. When nonanoic acid is used as antimicrobial agent according to the invention, as a rule no further antimicrobial agent will be required and according to one embodiment of the invention the food essentially contains exclusively nonanoic acid as antimicrobial agent, that is to say in the amounts specified above (in per cent by mass or ppm).
However, it can not be entirely precluded that in addition to the nonanoic acid minor amounts of one or more further antimicrobial agents known per se are present, such as the agents which are mentioned below. Therefore, "essentially exclusively" is defined as meaning that the nonanoic acid makes up at least 80 % (m m), preferably at least 90 % (m/m) and more preferentially at least 95 - 99 % (m/m) of all antimicrobial constituents present (that is to say added to the food in order to achieve an antimicrobial action).
Furthermore it is possible to use nonanoic acid in a mixture with one or more antimicrobial agents which are known per se and are compatible with nonanoic acid, a synergistic effect possibly being able to be obtained. In this case - compared with the use of the known agent as such - the nonanoic acid will as a rule replace some of the quantity of the known antimicrobial agent usually used.
Nonanoic acid will as a rule make up at least 30 % (m/m), preferably at least 50 % (m/m) and more preferentially at least 70 % (m m) of the total antimicrobial constituents in such mixtures.
A few non-limiting examples of antimicrobial agents that can be used according to the invention in combination with nonanoic acid are: sorbic acid and salts thereof, benzoic acid and salts thereof, para-hydroxybenzoic acid or esters thereof, propionic acid and salts thereof, pimaricin, polyethylene glycol, ethylene/propylene oxides, sodium diacetate, caprylic acid (octanoic acid), ethyl formate, tylosin, polyphosphate, metabisulphite, nisin, subtilin and diethyl pyrocarbonate.
The nonanoic acid can furthermore be used in combination with agents for adjusting the acidity, including the acids acceptable for foods, such as citric acid, acetic acid and the like. In this context the nonanoic acid can, in particular, protect the food (which in this case can have a pH in the range from 2 to 6) against acid-resistant moulds. Examples of such acid-resistant moulds are, but are not restricted to, Penicillium roqueforti, P. carneum, P. italicum, Monascus ruber and/or Paecilomyces variotii (which occur, for example, in rye bread); and Penicillium glandicola, Penicillium roqueforti, Aspergillus flavus, Aspergillus candidus and or Aspergillus terreus (which, for example, occur in products which have been preserved by acid, such as sour and/or sweet-sour preserves). More generally, according to the invention it is preferable that at least some, and preferably an appreciable proportion, of the nonanoic acid is present in the undissociated form in the food.
The general rule in this context is that the amount of undissociated nonanoic acid increases at lower pH: for instance, approximately 90 % of the nonanoic acid is present in undissociated form at a pH of approximately 3.8.
According to one aspect of the invention, nonanoic acid is therefore also used in foods which have a low pH, such as a pH in the range 2 to 6, preferably 3 to 5.8, or 4 to 5.6.
For instance, for example, the pH of cheese rind is around 4.8 - 5.3.
In addition to the antimicrobial, in particular antifungal, action described above, the use of nonanoic acid according to the invention can also yield the following further advantages: nonanoic acid is a stable molecule in both the dissociated and undissociated form.
The long alkyl chain is inert and renders the molecule barely reactive. nonanoic acid is a natural substance which occurs in plants, inter alia; - nonanoic acid has been approved for use in foods (inter alia by the FDA); nonanoic acid remains stable under the majority of processing steps/processes for food products; nonanoic acid is less susceptible to UV light than is, for example, natamycin; nonanoic acid is stable in the presence of metals in metallic form; - nonanoic acid is stable under heating.
The invention has been described above with reference to a preferred embodiment thereof; that is to say use in foods, in particular in dairy products.
However, it will be clear to those skilled in the art from the above description that nonanoic acid can also find use outside the food sector as an antifungal, yeast-inhibiting and/or antibacterial agent. In this context it will, in particular, be an advantage that nonanoic acid has been approved for use in foods, so that it can be used in applications where it can come into contact with foods or the human body, such as with the skin.
A number of possible, non-limiting applications are: use as or in disinfectant(s), cleaning agent(s) and the like, for both domestic and industrial applications; disinfection and/or cleaning (including preventive treatment) of conveyor belts, pallets and the like; disinfection and/or cleaning (including preventive treatment) of apparatus, products and/or surfaces which come into contact with foods, such as cutting machines, mixers, stirrers, sorting equipment, filling machines and other equipment from the food processing industry; vats, dishes, tanks, plates, containers and other holders; and also worktops, sink units and the like; both domestic and industrial; disinfection and/or cleaning (including preventive treatment) of areas which may or may not be enclosed, in particular areas in which food products are processed and/or stored, such as cupboards, refrigerators, kitchens, factory areas, freight areas, warehouses and the like (both domestic and industrial); and in particular cheese warehouses and other commercial premises where P. discolor can occur; coating and/or (preventive) treatment of packaging for, for example, foods (such as fruit, vegetables, cheese and the like), for example made of materials such as plastic, paper, cardboard or shaped cardboard; protection of fruit, such as oranges, lemons, grapefruit, apples, pears; nuts and
(dried) southern fruits, coffee, tea, tobacco and the like, and also of cut flowers and bulbs, against moulds and/or bacteria, before or during transport and/or during (long- term) storage, for example in a warehouse or in an (optionally) air-conditioned fruit store; disinfection and/or cleaning (including preventive treatment) of, for example, tents or tarpaulins, and also indoors (for example on walls) to prevent or to counteract mould growth, for example as a consequence of damp; protection and/or treatment of wood and similar materials; use in cosmetics and skincare products; use for pharmaceutical applications, for example to prevent and treat fungal infections and yeast infections, such as Candida. These aspects of the invention in general comprise the treatment of a surface or substrate that is susceptible to mould formation, or that can be contaminated or infected by a mould and/or the spores thereof, with an amount of nonanoic acid which has an effective antifungal and/or antibacterial action.
This amount will differ depending on the application and the way in which the nonanoic acid is used on the surface or substrate.
As a rule the presence of nonanoic acid in amounts of 10 - 10,000 ppm, in particular 100 - 2,000 ppm, will again be sufficient to achieve an antimicrobial, in particular antifungal, action, although higher concentrations can be used for some applications. The nonanoic acid can be used on the surface or substrate in any suitable way, such as, once again, spraying or brushing with nonanoic acid (for example in the form of an aqueous solution), by applying a nonanoic acid-containing coating or by use of an atomised spray containing nonanoic acid.
This treatment can optionally be repeated.
In this context the nonanoic acid can once again be used instead of, or together with, disinfectants which may be known for the envisaged application, as well as in combination with other agents or constituents customary for the envisaged application. For these applications, the nonanoic acid and any other constituents can optionally be marketed in a suitable container, for example in a bottle or in the form of a spray.
A particular application of nonanoic acid according to the invention furthermore relates to the control - in particular the inhibition - of bacterial growth during fermentation processes, such as the preparation of fermented food products such as yoghurt. For this application use is made in particular of the antibacterial action of nonanoic acid. For instance, nonanoic acid can be used to control the pH during or after such fermentation processes and in particular to prevent and/or reduce post-acidification of, for example, yoghurt, as explained in more detail in the examples.
The taste of the yoghurt is retained for longer as a result.
In addition, the antimicrobial, in particular antifungal, action according to the invention will also be obtained.
The invention will now be explained with reference to the following non-limiting examples and the figures, in which:
Figure 1 is a graph (time against visible intensity of mould formation) in which the effect of nonanoic acid on mould formation on Gouda cheese is shown; Figure 2 is a graph (time against number of bacteria) which shows the effect of nonanoic acid (pelargonic acid) on the development of yoghurt bacteria at 7 °C; -
Figure 3 is a graph (time against pH) which shows the effect of nonanoic acid (pelargonic acid) on the post-acidification of yoghurt at 7 °C; Figure 4 is a graph (time against number of bacteria) which shows the effect of nonanoic acid (pelargonic acid) on the development of yoghurt bacteria at 32 °C; Figure 5 is a graph (time against pH) which shows the effect of nonanoic acid (pelargonic acid) on the post-acidification of yoghurt at 32 °C;
Figure 6 is a plot (time against number of bacteria) that shows the influence of nonanoic acid (pelargonic acid) on the development of surface flora on cheese rind; Figure 7 is a plot (time against number) that shows the effect of nonanoic acid (pelargonic acid) on the development of D. hansenii, S. cereviseae, C. lipolytica and R. rubra;
Figures 8 A and 8B are photographs which show the effect of natamycin (Figure 8 A) and nonanoic acid (Figure 8B), respectively, on the inhibition of the growth of P. discolor on blocks of cheese rind;
Figure 9 is a graph (time against number of bacteria) which shows the effect of nonanoic acid on the growth of Bacillus cereus in soup;
Figure 10 is a graph (time against number of bacteria) which shows the effect of nonanoic acid on the growth of Staphylococcus aureus in soup;
Figure 11 is a graph (time against number of cells) which shows the effect of nonanoic acid on the growth of Debaromyces hansenii in a milk/fruit juice drink; Figure 2 is a graph (time against number of cells) which shows the effect of nonanoic acid on the growth of Penicillium italicum in a milk/fruit juice drink.
Experimental
Example 1 : Use of nonanoic acid in Gouda cheese
A trial production of Gouda cheeses was made. In this batch of cheeses one series was treated with 1000 ppm nonanoic acid (nonanoic acid) and the other series was not treated with a fungicide (blank). The two series were inoculated with spores of the mould P. discolor (0.1 spore/cm2) and stored at 13 °C and 88 % relative humidity. All individual cheeses were assessed visually at frequent intervals for the extent of the presence of mould. The following scale was used for the optical assessment of the intensity of visible moulds;
0 = no mould 1 = some mould
2 = distinct mould
3 = considerable mould
4 = very considerable mould or overgrown with mould.
The results are shown diagrammatically in Figure 1. In the case of the cheeses without fungicide slight mould growth (intensity 1) was detectable after about 60 days.
In the case of the series of cheeses treated with nonanoic acid it was 66 days before mould growth (intensity 1) was observed.
Example 2: Use of nonanoic acid in yoghurt to prevent post-acidification In an experiment various concentrations of nonanoic acid were added to freshly prepared yoghurt.
One series was monitored for 8 hours at the culture temperature (filling, 32 °C) and another series was incubated for 14 days at 7 °C (refrigerator temperature).
This was carried out to investigate the extent to which nonanoic acid has an effect during yoghurt fermentation and/or during storage of the filled packs of yoghurt.
For both series the pH was determined and the number of yoghurt bacteria.
The results are shown in Figures 2 - 5. Addition of 1,000 ppm nonanoic acid substantially prevented post-acidification (32 °C) and the number of yoghurt bacteria was reduced by 2 log units. At 7 °C an effect on the post-acidification was already detectable at lower nonanoic acid contents (200 ppm). Addition of 1,000 ppm prevented post- acidification Virtually completely when storing at refrigerator temperature and the number of yoghurt bacteria decreased by 4 log units.
Example 3: Effect of nonanoic acid on the surface flora of cheese rind
The effect of nonanoic acid on the surface flora on cheese rind was determined.
The results (time against number of bacteria) are shown in Figure 6.
The effect of nonanoic acid (pelargonic acid) on the development of D. hansenii, S. cereviseae, C. lipolytica and R. rubra was also determined.
The results (time against number) are shown in Figure 7.
Example 4: Use on blocks of cheese rind
In this experiment blocks of cheese rind were inoculated with P. discolor. The blocks were incubated at 20 °C and high relative humidity (95 %). These conditions were employed to provide the mould with the optimum opportunity to grow and are therefore more severe than the usual conditions for maturing cheese.
The results are given in Figure 8, which shows photographs of the blocks of cheese rind taken two weeks after inoculating with P. discolor.
One series was treated with natamycin (Figure 8A) and the other series with nonanoic acid (Figure 8B).
It can clearly be seen that after 2 weeks mould formation was inhibited in the blocks treated with nonanoic acid.
Example 5: Use in soup
In this experiment a creamy mushroom soup with parsley (chill-fresh product obtained from the Albert Heijn delicatessen in March 2000) was inoculated with
104 CFU/ml (colony-forming units per ml soup) of Bacillus cereus (NIZO B443) or with 104 CFU/ml Staphylococcus aureus (NIZO B1211).
The soup was then incubated at 20 °C, without and with increasing concentrations of nonanoic acid (100, 500 and 1,000 ppm).
Samples were taken at the times indicated in Figures 9 and 10 (Figure 9 for B. cereus and Figure 10 for S. aureus).
From each sample a series of dilutions was plated to determine the number of CFU/ml soup.
The B. cereus samples were plated on mannitol egg yolk polymyxin agar (MYP) and incubated for 24 hours at 30 °C; the S. aureus samples were plated on Baird-Parker egg yolk tellurite agar (BP) and incubated for 48 hours at 37 °C. The results are shown in Figures 9 and 10. The addition of 100 ppm nonanoic acid to the soup has a slightly inhibiting effect on the growth of both B. cereus and S. aureus, whilst with the addition of 500 or 1,000 ppm nonanoic acid the growth of both bacteria is virtually completely inhibited. Example 6: Use in a milk/fruit juice product
In this experiment a milk/fruit juice drink ("Milk & Fruit"™ from Coberco, obtained from Albert Heijn; "Milk & Fruit"™ is a chilled-fresh, pasteurised product without preservatives, consisting of 80 % drinking yoghurt and 20 % pineapple juice and has a pH value of 4.0) was inoculated with 102 CFU/ml Debaromyces hansenii (NIZO F937) or Penicillium italicum (CBS 278.58).
The milk/fruit juice drink was then incubated at 20 °C, without and with increasing concentrations of nonanoic acid (100, 500 and 1,000 ppm).
Samples were taken at the times indicated in Figures 11 and 12 (Figure 11 for D. hansenii and Figure 12 for P. italicum).
For each sample a series of dilutions was plated in order to determine the number of CFU/ml drink.
The samples were plated on oxytetracycline glucose yeast agar (OGY) and incubated for 5 days at 25 °C.
The results are shown in Figures 11 and 12. Addition of 100 ppm nonanoic acid gives complete inhibition of the growth of D. hansenii.
Addition of 100 or 500 ppm inhibits the growth of P. italicum and addition of 1,000 ppm nonanoic acid gives complete inhibition of the growth of P. italicum for up to 6 days.
GENERAL DESCRIPTION OF CARBOXYLIC ACID
Carboxylic acid is an organic compound whose molecules contain carboxyl group and have the condensed chemical formula R-C(=O)-OH in which a carbon atom is bonded to an oxygen atom by a solid bond and to a hydroxyl group by a single bond), where R is a hydrogen atom, an alkyl group, or an aryl group. Carboxylic acids can be synthesized if aldehyde is oxidized. Aldehyde can be obtained by oxidation of primary alcohol. Accordingly, carboxylic acid can be obtained by complete oxidation of primary alcohol. A variety of Carboxylic acids are abundant in nature and many carboxylic acids have their own trivial names. Examples are shown in table. In substitutive nomenclature, their names are formed by adding -oic acid' as the suffix to the name of the parent compound. The first character of carboxylic acid is acidity due to dissociation into H+ cations and RCOO- anions in aqueous solution. The two oxygen atoms are electronegatively charged and the hydrogen of a carboxyl group can be easily removed. The presence of electronegative groups next to the carboxylic group increases the acidity. For example, trichloroacetic acid is a stronger acid than acetic acid. Carboxylic acid is useful as a parent material to prepare many chemical derivatives due to the weak acidity of the hydroxyl hydrogen or due to the difference in electronegativity between carbon and oxygen. The easy dissociation of the hydroxyl oxygen-hydrogen provide reactions to form an ester with an alcohol and to form a water-soluble salt with an alkali. Almost infinite esters are formed through condensation reaction called esterification between carboxylic acid and alcohol, which produces water. The second reaction theory is the addition of electrons to the electron-deficient carbon atom of the carboxyl group. One more theory is decarboxylation (removal of carbon dioxide form carboxyl group). Carboxylic acids are used to synthesize acyl halides and acid anhydrides which are generally not target compounds. They are used as intermediates for the synthesis esters and amides, important derivatives from carboxylic acid in biochemistry as well as in industrial fields. There are almost infinite esters obtained from carboxylic acids. Esters are formed by removal of water from an acid and an alcohol. Carboxylic acid esters are used as in a variety of direct and indirect applications. Lower chain esters are used as flavouring base materials, plasticizers, solvent carriers and coupling agents. Higher chain compounds are used as components in metalworking fluids, surfactants, lubricants, detergents, oiling agents, emulsifiers, wetting agents textile treatments and emollients, They are also used as intermediates for the manufacture of a variety of target compounds. The almost infinite esters provide a wide range of viscosity, specific gravity, vapor pressure, boiling point, and other physical and chemical properties for the proper application selections. Amides are formed from the reaction of a carboxylic acids with an amine. Carboxylic acid's reaction to link amino acids is wide in nature to form proteins (amide), the principal constituents of the protoplasm of all cells. Polyamide is a polymer containing repeated amide groups such as various kinds of nylon and polyacrylamides. Carboxylic acid are in our lives.
ALIPHATIC CARBOXYLIC ACIDS
COMMON NAME
SYSTEMATIC NAME
CAS RN
FORMULA
MELTING POINT
Formic Acid Methanoic acid 64-18-6 HCOOH
8.5 C
Acetic Acid Ethanoic acid 64-19-7 CH3COOH
16.5 C
Carboxyethane Propionic Acid 79-09-4 CH3CH2COOH
-21.5 C
Butyric Acid n-Butanoic acid 107-92-6 CH3(CH2)2COOH
-8 C
Valeric Acid n-Pentanoic Acid 109-52-4 CH3(CH2)3COOH
-19 C
Caproic Acid n-Hexanoic Acid 142-62-1 CH3(CH2)4COOH
-3 C
Enanthoic Acid n-Heptanoic acid 111-14-8 CH3(CH2)5COOH
-10.5 C
Caprylic Acid n-Octanoic Acid 124-07-2 CH3(CH2)6COOH
16 C
alpha-Ethylcaproic Acid 2-Ethylhexanoic Acid 149-57-5 CH3(CH2)3CH(C2H5)COOH
-59 C
Valproic Acid 2-Propylpentanoic Acid 99-66-1 (CH3CH2CH2)2CHCOOH
120 C
Pelargonic Acid n-Nonanoic Acid 112-05-0 CH3(CH2)7COOH
48 C
Capric Acid n-Decanoic Acid 334-48-5 CH3(CH2)8COOH
31 C
Nonanoic acid is a fatty acid which occurs naturally as esters are the oil of pelargonium. Synthetic esters, such as methyl nonanoate, are used as flavorings. Pelargonic acid is an organic compound composed of a nine-carbon chain terminating in a carboxylic acid. It is an oily liquid with an unpleasant, rancid odor. It is nearly insoluble in water, but well soluble in chloroform and ether.
Nonanoic acid, also called pelargonic acid, is an organic compound with structural formula CH3(CH2)7CO2H. It is a nine-carbon fatty acid. Nonanoic acid is a colorless oily liquid with an unpleasant, rancid odor. It is nearly insoluble in water, but very soluble in organic solvents. The esters and salts of nonanoic acid are called nonanoates. Its refractive index is 1.4322. Its critical point is at 712 K (439 °C) and 2.35 MPa.
PELARGONIC ACID = NONANOIC ACID = NONYLIC ACID = PELARGIC ACID
EC / List no.: 203-931-2
CAS no.: 112-05-0
Mol. formula: C9H18O2
Nonanoic acid (frequently referred to as pelargonic acid) is a naturally occurring carboxylic acid with a carbon chain-length of nine, belonging to the chemical class of saturated fatty acids commonly referred to as medium chain fatty acids (C8 to C12).
Pelargonic acid is a clear, colourless liquid with a weak odour.
Pelargonic acid (Nonanoic acid) is soluble in aqueous solutions however it can readily form esters and partially dissociate into the pelargonate anion (CH3(CH2)7COO-) and the hydronium cation (H3O+) in an aqueous solution. The molecular weight (158.24 g/mol) and octanol-water partition coefficient (3.4 logPow) of nonanoic acid suggest that dermal penetration is possible.
Nonanoic acid is a medium-chain saturated fatty acid.
Nonanoic acid inhibits mycelial growth and spore germination in the plant pathogenic fungi M. roreri and C. perniciosa in a concentration-dependent manner.It has herbicidal activity against a variety of species, including crabgrass.
Nonanoic acid has been used as an internal standard for the quantification of free fatty acids in olive mill waste waters.
Formulations containing nonanoic acid have been used in indoor and outdoor weed control and as cleansing and emulsifying agents in cosmetics.
Pelargonic acid, also called nonanoic acid, is an organic compound with structural formula CH3(CH2)7CO2H.
Pelargonic acid is a nine-carbon fatty acid. Nonanoic acid is a colorless oily liquid with an unpleasant, rancid odor.
Pelargonic acid is nearly insoluble in water, but very soluble in organic solvents.
The esters and salts of pelargonic acid are called pelargonates or nonanoates.
Pelargonic acid is used in herbicide formulations and in the preparation of plasticizers, resins, lubricants, and lacquers
Pelargonic acid or Nonanoic Acid is a C9 straight-chain saturated fatty acid which occurs naturally as esters of the oil of pelargonium.
Pelargonic acid has antifungal properties, and is also used as a herbicide as well as in the preparation of plasticisers and lacquers.
Nonanoic Acid is a naturally-occurring saturated fatty acid with nine carbon atoms. The ammonium salt form of nonanoic acid is used as an herbicide.
Nonanoic Acid works by stripping the waxy cuticle of the plant, causing cell disruption, cell leakage, and death by desiccation.
Nonanoic acid is a C9 straight-chain saturated fatty acid which occurs naturally as esters of the oil of pelargonium.
Nonanoic acid has antifungal properties, and is also used as a herbicide as well as in the preparation of plasticisers and lacquers.
Nonanoic acid has a role as an antifeedant, a plant metabolite, a Daphnia magna metabolite and an algal metabolite.
Nonanoic acid is a straight-chain saturated fatty acid and a medium-chain fatty acid. It is a conjugate acid of a nonanoate. Nonanoic acid derives from a hydride of a nonane.
Nonanoic acid (Pelargonic acid, Nonoic acid) is a naturally occurring fatty acid found in both vegetable and animal fats.
Nonanoic acid (NNA) is a medium chain fatty acid, and is a naturally occurring carboxylic acid with a carbon chain length of nine.
Nonanoic acid is used in agricultural and veterinary (AgVet) chemical products as an herbicide, and may have other uses in therapeutic goods or fragrances.
Nonanoic acid has been used in a range of agricultural chemicals as an herbicide, both in combination with other actives (particularly glyphosate), but also as a stand-alone active constituent.
Commercial products are available with high concentrations of Nonanoic acid. Nonanoic acid is available as products for use in the home garden, both in ready to use formulations and also as concentrated formulations which require dilution prior to use.
Pelargonic acid, also known as nonanoic acid or pelargon, belongs to the class of organic compounds known as medium-chain fatty acids.
These are fatty acids with an aliphatic tail that contains between 4 and 12 carbon atoms.
Pelargonic acid is an oily liquid with an unpleasant, rancid odor.
It is a very hydrophobic molecule, practically insoluble in water but very soluble in organic solvents.
The biosynthesis of fatty acid occurs through the acetate pathway and the process is catalyzed by the Fatty Acid Synthase (FAS) enzymes.
Structurally, FAS varies significantly across different organisms but essentially, they all perform the same task using the same mechanisms.
Nonanoic acid is also used in the preparation of plasticizers and lacquers. Synthetic esters of nonanoic acid, such as methyl nonanoate, are used as flavorings.
The derivative 4-nonanoylmorpholine is an ingredient in some pepper sprays. The ammonium salt of nonanoic acid, ammonium nonanoate, is an herbicide.
It is commonly used in conjunction with glyphosate, a non-selective herbicide, to control weeds in turfgrass.
Pelargonic acid is a clear to yellowish oily liquid. It is insoluble in water but soluble in ether, alcohol and organic solvents.
The molecules of most natural fatty acids have an even number of carbon chains due to the linkage together by ester units.
Analogous compounds of odd numbers carbon chain fatty acids are supplemented synthetically.
Pelargonic acid, C-9 odd numbers carbon chain fatty acid, is relatively high cost fatty acid.
Pelargonic acid can be prepared by ozonolysis which uses ozone is to cleave the alkene bonds.
Example of ozonolysis in commerce is the production of odd carbon number carboxylic acids such as azelaic acid and pelargonic acid and simple carboxylic acids such as formic acid and oxalic acid.
Pelargonic acid forms esters with alcohols to be used as plasticizers and lubricating oils.
It is used in modifying alkyd resins to prevent discolor and to keep flexibility and resistance to aging since saturated pelargonic acid will not be oxidized.
Metallic soaps (barium and cadmium) and other inorganic salts used as a stabilizer.
It is also used as a chemical intermediate for synthetic flavors, cosmetics, pharmaceuticals and corrosion inhibitors.
It is known that C8 - C12 straight and saturated chain fatty acids are capable of removing the waxy cuticle of the broadleaf or weed, resulting in causing the tissue death. T
hey are used as active ingredient of environment friendly and quick effect herbicides. Pelargonic acid is the strongest one.
Nonanoic acid may be used to treat seizures (PMID 23177536).
Other names: n-Nonanoic acid; n-Nonoic acid; n-Nonylic acid; Nonoic acid; Nonylic acid; Pelargic acid; Pelargonic acid; 1-Octanecarboxylic acid; Cirrasol 185a; Emfac 1202; Hexacid C-9; Pelargon; Emery 1203; 1-Nonanoic acid; NSC 62787; n-Pelargonic acid; Emery 1202 (Salt/Mix)
IUPAC Name: nonanoic acid
Synonyms:
1-nonanoic acid
1-octanecarboxylic acid
CH3‒[CH2]7‒COOH IUPAC
n-nonanoic acid
n-nonanoic acid
Nonanoate
Nonanoic acid
Nonansäure Deutsch
nonoic acid
nonylic acid
pelargic acid
pelargon
Pelargonic acid
Pelargonsäure Deutsch
pergonic acid
nonanoic acid has parent hydride nonane
nonanoic acid has role Daphnia magna metabolite
nonanoic acid has role algal metabolite
nonanoic acid has role antifeedant
nonanoic acid has role plant metabolite
nonanoic acid is a medium-chain fatty acid
nonanoic acid is a straight-chain saturated fatty acid
nonanoic acid is conjugate acid of nonanoate
SYNONYMS :
NONANOIC ACID
Pelargonic acid
112-05-0
n-Nonanoic acid
Nonoic acid
Nonylic acid
Pelargic acid
n-Nonylic acid
n-Nonoic acid
1-Octanecarboxylic acid
Pelargon
Cirrasol 185A
Hexacid C-9
Emfac 1202
1-nonanoic acid
Fatty acids, C6-12
Fatty acids, C8-10
Nonansaeure
Pelargonsaeure
pergonic acid
MFCD00004433
nonoate
NSC 62787
UNII-97SEH7577T
68937-75-7
CH3-[CH2]7-COOH
CHEBI:29019
97SEH7577T
pergonate
n-nonanoate
1-nonanoate
C9:0
octan-1 carboxylic acid
1-octanecarboxylate
n-Nonanoic acid, 97%
DSSTox_CID_1641
DSSTox_RID_76255
DSSTox_GSID_21641
Pelargon [Russian]
1-Octanecarboxyic acid
CAS-112-05-0
FEMA No. 2784
HSDB 5554
EINECS 203-931-2
EPA Pesticide Chemical Code 217500
BRN 1752351
n-Pelargonate
AI3-04164
n-Nonylate
Perlargonic acid
n-Nonoate
n-pelargonic acid
KNA
EINECS 273-086-2
Nonanoic Acid Anion
Acid C9
Caprylic-Capric Acid
Nonanoic acid, 96%
3sz1
Emery's L-114
Pelargonic Acid 1202
Emery 1202
Emery 1203
octane-1-carboxylic acid
Preparation, occurrence, and uses
Pelargonic acid occurs naturally as esters in the oil of pelargonium.
Together with azelaic acid, it is produced industrially by ozonolysis of oleic acid.
H17C8CH=CHC7H14CO2H + 4O → HO2CC7H14CO2H + H17C8CO2H
Synthetic esters of pelargonic acid, such as methyl pelargonate, are used as flavorings.
Pelargonic acid is also used in the preparation of plasticizers and lacquers.
The derivative 4-nonanoylmorpholine is an ingredient in some pepper sprays.
The ammonium salt of pelargonic acid, ammonium pelargonate, is an herbicide.
It is commonly used in conjunction with glyphosate, a non-selective herbicide, for a quick burn-down effect in the control of weeds in turfgrass.
Pharmacological effects
Pelargonic acid may be more potent than valproic acid in treating seizures.
Moreover, in contrast to valproic acid, pelargonic acid exhibited no effect on HDAC inhibition, suggesting that it is unlikely to show HDAC inhibition-related teratogenicity.
IUPAC name: Nonanoic acid
Other names: Nonoic acid; Nonylic acid;
1-Octanecarboxylic acid;
C9:0 (Lipid numbers)
Identifiers
CAS Number: 112-05-0
EC Number: 203-931-2
Properties
Chemical formula: C9H18O2
Molar mass: 158.241 g·mol−1
Appearance: Clear to yellowish oily liquid
Density: 0.900 g/cm3
Melting point: 12.5 °C (54.5 °F; 285.6 K)
Boiling point: 254 °C (489 °F; 527 K)
Critical point (T, P): 439 °C (712 K), 2.35 MPa
Solubility in water: 0.3 g/L
Acidity (pKa): 4.96
1.055 at 2.06 to 2.63 K (−271.09 to −270.52 °C; −455.96 to −454.94 °F)
1.53 at −191 °C (−311.8 °F; 82.1 K)
Refractive index (nD): 1.4322
Hazards
Main hazards: Corrosive (C)
R-phrases (outdated): R34
S-phrases (outdated): (S1/2) S26 S28 S36/37/39 S45
Flash point: 114 °C (237 °F; 387 K)
Autoignition temperature: 405 °C
Categories: Alkanoic acids
Herbicides
Pelargonic Acid
Pelargonic acid is found naturally in pelargoniums and is a highly effective fatty acid widely used in the treatment of unwanted plants.
How does Pelargonic Acid work?
Pelargonic acid destroys the cell walls of the leaves of the weed.
This results in the cells losing their structure and drying out within a short space of time, under normal conditions this will be visible within 1 day after treatment.
Only the green parts of the plant are affected by this action, the woody bark of the plant is unaffected as the cells are too stable and the active ingredient has no way of penetrating the surface.
Therefore the product can be used under hedges, trees and bushes without fear of destroying the whole area.
Uses
Pelargonic acid occurs naturally in many plants and animals.
Pelargonic acid is used to control the growth of weeds and as a blossom thinner for apple and pear trees.
Pelargonic acid is also used as a food additive; as an ingredient in solutions used to commercially peel fruits and vegetables.
Pelargonic acid is present in many plants.
Pelargonic acid is used as an herbicide to prevent growth of weeds both indoors and outdoors, and as a blossom thinner for apple and pear trees.
The U.S. Food and Drug Administration (FDA) has approved this substance for use in food.
No risks to humans or the environment are expected when pesticide products containing pelargonic acid are used according to the label directions.
I. Description of the Active Ingredient Pelargonic acid is a chemical substance that is found in almost all species of animals and plants.
Because it contains nine carbon atoms, it is also called nonanoic acid.
It is found at low levels in many of the common foods we eat.
It is readily broken down in the environment.
II. Use Sites, Target Pests, And Application Methods Pelargonic acid has two distinct uses related to plants: weed killer and blossom thinner.
[Note: The substance can also be used as a sanitizer, a use not addressed in this Fact Sheet.]
o Weed killer Growers spray pelargonic acid on food crops and other crops to protect them against weeds.
For food crops, pelargonic acid is allowed to be applied from planting time until 24 hours before harvest.
The pre-harvest restriction assures that little or no residue remains on the food.
The chemical also controls weeds at sites such as schools, golf courses, walkways, greenhouses, and various indoor sites.
o Blossom thinner Growers use pelargonic acid to thin blossoms, a procedure that increases the quality and yield of apples and other fruit trees.
Thinning the blossoms allows the trees to produce fruit every year instead of every other year.
III. Assessing Risks to Human Health Pelargonic acid occurs naturally in many plants, including food plants, so most people are regularly exposed to small amounts of this chemical.
The use of pelargonic acid as an herbicide or blossom thinner on food crops is not expected to increase human exposure or risk.
Furthermore, tests indicate that ingesting or inhaling pelargonic acid in small amounts has no known toxic effects.
Pelargonic acid is a skin and eye irritant, and product labels describe precautions that users should follow to prevent the products from getting in their eyes or on their skin.
THE USE OF PELARGONIC ACID AS A WEED MANAGEMENT TOOL
Steven Savage and Paul Zomer Mycogen Corporation, San Diego, California In 1995, the Mycogen Corporation introduced Scythe®, a burn-down herbicide containing 60% of the active ingredient, pelargonic acid.
Pelargonic acid is a naturally occurring, saturated, nine-carbon fatty acid (C9:0).
Pelargonic acid occurs widely in nature in products such as goat's milk, apples and grapes.
Commercially it is produced by the ozonolysis of oleic acid (C18:1) from beef tallow.
Pelargonic acid has very low mammalian toxicity (oral, inhalation), is not mutagenic, teratogenic or sensitizing.
It can cause eye and skin irritation and thus the formulated product carries a WARNING signal word (Category II).
It has a benign environmental profile. As a herbicide, pelargonic acid causes extremely rapid and non-selective burn-down of green tissues.
The rate of kill is related to temperature, but under all but the coolest conditions the treated plants begin to exhibit damage within 15-60 minutes and begin to collapse within 1-3 hours of the application.
Pelargonic acid is not systemic and is not translocated through woody tissues.
It is also active against mosses and other cryptograms. Pelargonic acid has no soil activity.
As with most burn-down herbicides, pelargonic acid does not prevent re-growth from protected buds or basal meristems.
Many annual herbaceous weeds can be killed completely while larger weeds, grasses and woody plants may re-grow.
There are many practical applications of the rapid burn-down activity of pelargonic acid.
It can be used for spot weeding, edging, lining, turf renewal, chemical pruning and suckering.
It is particularly useful as a directed spray for killing annual weeds in container-grown woody ornamentals, under greenhouse benches and in other places where systemic herbicides can cause unwanted damage.
If the spray of pelargonic acid does come in contact with some desired plants, the damage is strictly limited to those leaves which are actually sprayed.
Pelargonic acid should be applied in at least 75 gallons/acre of total spray volume as activity declines at lower gallonages.
Evidence from P31 NMR studies suggests that the mode of action of pelargonic acid is not based on direct damage to cell membranes.
Pelargonic acid moves through the cuticle and cell membranes and lowers the internal pH of the plant cells.
Over the next several minutes the pools of cellular ATP and Glucose-6-phosphate decline.
Only later is there evidence of membrane dysfunction which eventually leads to cell leakage, collapse and desiccation of the tissue.
This chain of cellular events appears to allow pelargonic acid to synergize the activity of certain systemic herbicides such as glyphosate.
In general, bum-down herbicides are antagonistic to the activity of systemic herbicides, but in a tank mix pelargonic acid has been shown to allow greater and more rapid uptake of glyphosate without interfering with translocation.
This type of synergy is completely distinct from the enhancement seen with various surfactants used as adjuvants or formulation components for glyphosate.
By using high volume applications of a tank mix it is possible to combine the rapid kill of pelargonic acid with the systemic action of glyphosate.
At low application volumes (e.g. 20-30 GPA), pelargonic acid still enhances glyphosate uptake and improves its overall performance, but there is no immediate burn of the treated foliage.
Scythe herbicide was registered for non-crop use in 1995 and a crop registration is expected in 1996.
This commercial formulation of pelargonic acid has a wide range of weed control applications both as a contact, non-selective agent and as a tank mixing partner with systemic herbicides such as glyphosate.
The Herbicidal Potential of Different Pelargonic Acid Products and Essential Oils against Several Important Weed Species
Ilias Travlos 1,* , Eleni Rapti 1 , Ioannis Gazoulis 1 , Panagiotis Kanatas 2 , Alexandros Tataridas 1 , Ioanna Kakabouki 1 and Panayiota Papastylianou 1 1
Laboratory of Agronomy, Department of Crop Science, Agricultural University of Athens, 75 Iera Odos str., 118 55 Athens, Greece;
Published: 30 October 2020
Abstract: There is growing consideration among farmers and researchers regarding the development of natural herbicides providing sufficient levels of weed control.
The aim of the present study was to compare the efficacy of four different pelargonic acid products, three essential oils and two natural products’ mixtures against L. rigidum Gaud., A. sterilis L. and G. aparine L. Regarding grass weeds, it was noticed at 7 days after treatment that PA3 treatment (pelargonic acid 3.102% w/v + maleic hydrazide 0.459% w/v) was the least efficient treatment against L. rigidum and A. sterilis. The mixture of lemongrass oil and pelargonic acid resulted in 77% lower dry weight for L. rigidum in comparison to the control. Biomass reduction reached the level of 90% as compared to the control in the case of manuka oil and the efficacy of manuka oil and pelargonic acid mixture was similar.
For sterile oat, weed biomass was recorded between 31% and 33% of the control for lemongrass oil, pine oil, PA1 (pelargonic acid 18.67% + maleic hydrazide 3%) and PA4 (pelargonic acid 18.67%) treatments. In addition, the mixture of manuka oil and pelargonic acid reduced weed biomass by 96% as compared to the control.
Regarding the broadleaf species G. aparine, PA4 and PA1 treatments provided a 96–97% dry weight reduction compared to the corresponding value recorded for the untreated plants.
PA2 (pelargonic acid 50% w/v) treatment and the mixture of manuka oil and pelargonic acid completely eliminated cleaver plants.
The observations made for weed dry weight on the species level were similar to those made regarding plant height values recorded for each species.
Further research is needed to study more natural substances and optimize the use of natural herbicides as well as natural herbicides’ mixtures in weed management strategies under different soil and climatic conditions. Keywords: bioherbicide; pelargonic acid; manuka oil; lemongrass oil; pine oil; grass weeds; broadleaf weeds 1.
Introduction Weeds are considered to be one of the major threats to agricultural production since they affect the crop production indirectly, by competing with the crop for natural resources, sheltering crop pests, reducing crop yields and quality, and subsequently increasing the cost of processing [1]. Chemical control remains the most common control practice for weed management. Unfortunately, this overreliance on herbicides has led to serious problems, such as the possible injury to non-target vegetation and crops, the existence of herbicide residues in the water and the soil and concerns for human health and safety [2–5].
Another major issue associated with the use of synthetic herbicide is Agronomy 2020, 10, 1687; doi:10.3390/agronomy10111687 www.mdpi.com/journal/agronomy Agronomy 2020, 10, 1687 2 of 13 the growing problem of herbicide resistance since many harmful weed species including Amaranthus, Conyza, Echinochloa, and Lolium spp. are notorious for their ability to rapidly evolve resistance to a wide range of herbicide sites of action.
The development of natural herbicides based on either organic acids or essential oils could decrease these negative impacts.
They are less persistent in comparison to synthetic herbicides, more environmentally friendly, and they also have different modes of action which can prevent the development of herbicide-resistant weed biotypes [7,8]. Organic acids, essential oils, crude botanical products and other natural substances derived from plant tissues can be used as bio-herbicides in terms of weed management in both organic and sustainable agriculture systems [9].
Such natural substances face several opponents among the European Commission members, since there are doubts regarding the registration processes of natural products due to the lack of relevant toxicological data for their use at commercial scale [10]. Although these concerns might exist, there is evidence that most essential oils and their main compounds are not necessarily genotoxic or harmful to human health [11]. Such natural herbicides are sometimes less hazardous for environmental and human health in comparison to the commercial synthetic herbicides.
In the case of pelargonic acid, toxicity tests on non-target organisms, such as birds, fish, and honeybees, revealed little or no toxicity.
The chemical decomposes rapidly in both land and water environments, so it does not accumulate.
To minimize drift and potential harm to non-target plants, users are required to take precautions such as avoiding windy days and using large spray droplets.
However, product labels describe precautions that users should follow to prevent the products from getting in their eyes or on their skin since the acid is a skin and eye irritant [13].
Pelargonic acid (PA) (CH3(CH2)7CO2H, n-nonanoic acid) is a saturated, nine-carbon fatty acid (C9:0) naturally occurring as esters in the essential oil of Pelargonium spp. And can be derived from the tissues of various plant species [14–16]. Pelargonic acid along with its salts and formulated with emulsifiers is used in terms of weed management as a nonselective herbicide suitable either for garden or professional uses worldwide [8,14].
They are applied as contact burndown herbicides, which attack cell membranes and then as a result, cell leakage is caused and followed by membrane acyl lipids breakdown .
The phytotoxic effects due to the application of pelargonic acid are visible in a very short time after spraying and the symptoms involve phytotoxicity for the plants and their cells, which rapidly begin to oxidize, and necrotic lesions are observed on the aerial parts of plants [18].
The potential use of pelargonic acid as a bioherbicide poses an attractive non-chemical weed control option which can be effectively integrated with other eco-friendly weed management strategies in important crops such as soybean [19]. Several commercial pelargonic acid-based natural herbicides include also maleic hydrazide (1,2-dihydro-3,6-pyridazinedione) which is a systemic plant growth regulator that has also been used as a herbicide since its introduction [20].
Maleic hydrazide (1, 2-dihydropyridazine-3, 6-dione), a hormone-like substance synthesized and first introduced to USA in 1949, with crystal structure and structural similarity to the pyrimidine base uracil [20–22].
After application to foliage, maleic hydrazide is translocated in the meristematic tissues, with mobility in both phloem and xylem.
Although its mode of action is not clear, it can be used effectively for sprout suppression on vegetable crops such as onions and carrots as well as for the control of troublesome parasitic weed species where synthetic herbicides are limited [24–26]. Essential oils derived from a variety of aromatic, biomass, invasive or food crop plants are also known to have potential as natural non-selective herbicides [9,27–29].
Similarly, with the case of pelargonic acid, the foliage of weeds burns down in a very short time after application, which is more effective against young plants than older ones [30].
Manuka oil is isolated from the leaves of Leptospermum scoparium J. R. Forst. and G. Forst. and is considered to be an acceptable product in terms of organic standards [9].
The active ingredient in this essential oil is leptospermone, a natural b-triketone, which targets the enzyme p-hydroxyphenylpyruvate dioxygenase (HPPD) such as the conventional synthetic herbicides mesotrione and sulcotrione [31–33]. Lemongrass essential oil, derived from either Cymbopogon citratus Stapf. or C. flexuosus D.C. containing up to 80% citral is also commercialized Agronomy 2020, 10, 1687 3 of 13 as an organic herbicide whose mode of action involves the disruption of polymerization of plant microtubules [34].
Lemongrass oil acts as a contact herbicide, and since the active ingredient does not translocate, only the portions of plants receiving the spray solution are affected.
Pine essential oil is also commercialized as a 10% aqueous emulsion for weed control as a natural herbicide.
It is derived from steam distillation of needles, twigs and cones of Pinus sylvestris L. and a wide range of other species belonging to Pinus spp. and includes terpene alcohols and saponified fatty acids. Monoterpenes such as a- and b-pinene can increase the concentration of malondialdehyde, proline and hydrogen peroxide, indicating lipid peroxidation and induction of oxidative stress in weeds [35,36].
The aim of the present study was to evaluate and compare the efficacy of four different pelargonic acid products, three essential oils and two mixtures (of a pelargonic acid product and two essential oils) against three target weed species, i.e., rigid ryegrass (Lolium rigidum Gaud.), sterile oat (Avena sterilis L.) and cleaver (Galium aparine L.).
2. Materials and Methods 2.1. Plant Material Collection and Seed Pretreatment Seeds of rigid ryegrass (L. rigidum), sterile oat (A. sterilis) and cleaver (G. aparine) were collected from winter wheat fields of the origins of Fthiotida, Viotia and Larisa, respectively, during June 2019 (Table 1).
In each field, panicles and seeds were collected from 20 plants and transferred to the Laboratory of Agronomy (Agricultural University of Athens).
Table 1. Weed species studied, origins and geographical positions where seed collection was carried out. Common Name Scientific Name Origin Position Rigid ryegrass Lolium rigidum Gaud. Fthiotida 39◦08007” N, 22◦24056” E Sterile oat Avena sterilis L. Viotia 38◦24041” N, 23◦00040” E Cleaver Galium aparine L. Larisa 39◦25051” N, 22◦45047” E Two experiments were conducted and repeated twice to evaluate and compare the efficacy of the different pelargonic acid products, essential oils and mixtures of natural herbicides against the three target weed species.
The collected seeds were air-dried, threshed, placed in paper bags, and stored at room temperature to be used in the subsequent experimental runs.
Different were the seed pretreatment processes carried out to release dormancy in the seeds of the grasses and in the seeds of cleaver.
To release dormancy in the seeds of rigid ryegrass and sterile oat, the seeds were individually nicked with 2 teeth tweezers and placed in Petri dishes on two sheets of Whatman No.1 paper filter disk (Whatman Ltd., Maidstone, England) saturated with 6 mL distilled water, in 10 November. The Petri dishes were kept at 2–4 ◦C (refrigerator) for a period of 7 days. After that, the non-dormant seeds were used for sowing during the first experimental run, carried out during 2019. About half of the total collected grass weed seeds had been stored at room temperature to be used in the second experimental run, carried out during 2020. For cleaver, the seeds were sown in rectangular pots (28 × 30 × 70 cm3 ) and buried into the soil at approximately 3–4 cm depth, in 17 June. The pots were kept outside under natural conditions for 3 months to break the dormancy in the cleaver seeds.
The seeds were carefully removed from the pots in 19 September.
Afterwards, they were air-dried, placed and stored in paper bags at room temperature until use either for the first or the second experimental run.
Approximately fifteen seeds of rigid ryegrass and sterile oat, and twenty seeds of cleaver were sown in separate pots (12 × 13 × 15 cm3 ) in 18 November 2019, during the experiments of the first run. Rigid ryegrass and sterile oat seeds were sown at 1 cm depth.
Cleaver seeds were also sown at 1 cm depth to achieve maximum seedling emergence.
Pots had been filled with a mix of herbicide–free soil from the experimental field of the Agricultural University of Athens and peat at the ratio of 1:1 (v/v).
The soil of the experimental field is clay loam (CL) with pH value of 7.29, whereas the contents of CaCO3 and organic matter were 15.99% and 2.37%, respectively.
Moreover, the concentrations of NO3 − Agronomy 2020, 10, 1687 4 of 13 P (Olsen) and Na+ were 104.3, 9.95 and 110 ppm, respectively.
When the weed seedlings of all the weed species reached the appropriate phenological stage for spraying, they were carefully thinned to twelve plants per pot.
All pots were watered as needed and placed outdoors. The pots were randomized every 5 days in order to achieve uniform growth conditions for all the plants.
Regarding the duration of the first experiment, it was conducted between 18 November and 28 December 2019.
Regarding the second experimental run, the pot experiments were established in 14 January 2020 and were conducted until 25 February 2020.
For the second experimental run, the same courses of action were carried out regarding seed pretreatment and experiment establishment as compared to the corresponding ones carried out for the run. Typical climatic conditions for Greece were observed during the experimental periods.
Maximum month temperatures for November, December, January and February were 21.3, 15.6, 9.2 and 11.3 ◦C, respectively.
Minimum month temperatures for the same months were 14.2, 9.2, 2.1 and 1.8 ◦C, respectively, whereas total heights of precipitation for these months were 120.4, 90.6, 16.4 and 12.0 mm, respectively. 2.2. Experimental Treatments Several pelargonic acid products along with essential oils with a potential herbicidal action have been used. In particular, PA1 (3Stunden Bio-Unkrautfrei, Bayer Garten, Germany) and PA2 (Beloukha Garden, Belchim Crop Protection NV/SA, Technologielaan 7, 1840 Londerzeel, Belgium) contained only pelargonic acid at concentrations shown in Table 2, while PA3 and PA4 (Finalsan Ultima, W. Neudorff GmbH KG, Emmerthal, Germany) contained pelargonic acid along with maleic hydrazide (Table 2). For PA1, PA2, PA3 and PA4 treatments, pelargonic acid was applied as a single treatment without being mixed. Regarding the treatments containing essential oil application, EO1 (Manuka oil, Leptospermum scoparium, Salvia, India), EO2 (Lemon grass oil, Cymbopogon citratus, Sheer Essence, India) and EO3 (Pine oil, Pinus sylvestris, Sheer Essence, India) were used at 5% concentration.
All of the essential oils were diluted with water before treatment to achieve a 5% concentration.
In fact, commercial essential oils must be applied at high concentrations, often 10% or more per volume [30].
In the present study, an intermediate concentration of 5% was selected to reduce the cost of essential oil application in order to evaluate whether sufficient weed control can be achieved with the application of such natural herbicides at lower concentrations, acceptable also by an economic aspect. All herbicide applications were carried out with a handy pressure sprayer equipped with a variable conical nozzle.
Spraying was carried out at 0.3 MPa pressure and the spraying angle was 80◦ .
The height between the conical nozzle and the soil level was 40 cm for all the experimental treatments.
The spray head was set to move over the plants at 1.5 km h−1 and the apparatus was calibrated to deliver the equivalent of 200 L ha−1 .
The treatments were applied in 20 December, 2019, for the two runs of the first year (in 16 February 2020, for the two runs of the second year) when plants had reached the phenological stage of 2–3 true leaves, corresponding to stage 12–13 of the BBCH scale for rigid ryegrass and sterile oat, and the phenological stage of 3–4 true leaves, corresponding to stage 13–14 of the BBCH scale for cleaver. The pots were placed outdoors, and the leaves of the weed plants were vertically oriented at the time of spraying.
The experimental treatments were carried out at a sunny day and air temperature during spraying was 16.1 ◦C, for the first year (13.4 ◦C for the second year).
Table 2. The experimental treatments (e.g., natural herbicides) applied in the current study.
Treatment Active Ingredient Content in (g/L) or (mL/L) Dose Rate (L/ha) Active Ingredient per Unit Area in (g/ha) or (mL/ha) Abbreviation Control - - - -
Pelargonic acid 18.67% 18.67 1 200 3734 3 PA1 Pelargonic acid 50% 50 1 200 10000 3 PA2 Pelargonic acid 3.102% + maleic hydrazide 0.459% 3.102 1 200 620.4 3 PA3 Pelargonic acid 18.67% + maleic hydrazide 3% 18.67 1 + 3 1 200 3734 3 + 600 3 PA4 Agronomy 2020, 10, 1687 5 of 13
Table 2. Cont. Treatment Active Ingredient Content in (g/L) or (mL/L) Dose Rate (L/ha) Active Ingredient per Unit Area in (g/ha) or (mL/ha) Abbreviation Manuka oil 5% 5 2 200 1000 4 EO1 Lemongrass oil 5% 5 2 200 1000 4 EO2 Pine oil 5% 5 2 200 1000 4 EO3 Pelargonic acid 18.67% + maleic hydrazide 3% + Manuka oil 5% 18.67 1 + 3 1 + 5 2 200 3734 3 + 600 3 + 1000 4 M1 Pelargonic acid 18.67% + maleic hydrazide 3% + Lemongrass oil 5% 18.67 1 + 3 1 + 5 2 200 3734 3 + 600 3 + 1000 4 M2 1 Data refer to the active ingredient contents of the four different pelargonic acid formulations. The active ingredients are expressed in g/L. 2
Data refer to the active ingredient contents of the three different essential oil formulations.
The active ingredients are expressed in mL/L. 3 Data refer to the amount of the active ingredient of the four different pelargonic acid formulations per unit area.
The amounts are expressed in g/ha. 4 Data refer to the amount of the active ingredient of the three different essential oil formulations.
The amounts are expressed in mL/ha.
2.3. Evaluation of the Efficacy of Each Natural Herbicide against Targeted Weeds To evaluate the efficacy of each natural herbicide against the targeted weed species, dry weight and plant height of four plants per pot were measured for each weed species at 1, 3 and 7 days after treatment (DAT).
For measuring dry weight, the selected plants were dried at 60 ◦C for 48 h and then the measurements of dry weight were carried out.
The scale to measure dry weight had an accuracy of three decimal places and plant height was measured to nearest cm.
Each one of the experiments started with twelve plants in each pot and four plants were removed from each pot at 1, 3 and 7 DAT.
The assessment period was not longer than 7 DAT because the current experiment was focused on evaluating the knockdown effect of the natural herbicides on each one of the studied weed species. No observations regarding necrosis levels or NDVI values were made since these will be the objects of future experimentation. 2.4. Statistical Analysis Both of the experiments were repeated twice per year.
All the experiments were conducted in a completely randomized design with four replicates and nine experimental treatments (PA1, PA2, PA3, PA4, EO1, EO2, EO3, M1 and M2).
Four replicate pots were used for the evaluation of the effects of the experimental treatments on each weed species.
For all the experiments, the weed dry weight as well as the plant height values which corresponded to each treatment were measured, for each weed species separately. These values were recorded at 1, 3 and 7 DAT, and expressed as percentages of the corresponding values recorded for the untreated control plants.
An analysis of variance (ANOVA) combined over years and runs was conducted for all data and differences between means were compared at the 5% level of significance using the Fisher’s Protected LSD test. The ANOVA indicated no significant treatment x year interactions, across the two experimental runs, for each one of the weed species studied. Thus, the means of plant dry weight and height, for each weed species, were averaged over the two years and the two experimental runs.
Afterwards, the pooled data were analyzed by ANOVA at a ≤5% probability level using Statgraphics® Centurion XVI.
Fisher’s Protected LSD test was used to separate means regarding the effects of the application of the experimental treatments on plant dry weight and height for each one of the weed species studied.
3. Results 3.1. Effects of the Experimental Treatments on L. rigidum Dry Weight and Height In the first measurement carried out at 1 DAT, it was noticed that PA3 reduced dry weight of rigid ryegrass by 41% as compared to the control whereas biomass reduction was by 13% higher in the case of PA1.
The efficacy of manuka, lemongrass and pine essential oils was similar.
The mixture of manuka oil and pelargonic acid resulted in 63% lower rigid ryegrass dry weight than the value recorded for the untreated plants whereas similar was the efficacy of the mixture of lemongrass essential oil and pelargonic acid. In the second measurement, carried out at 3 DAT, it was revealed that PA3 resulted in Agronomy 2020, 10, 1687 6 of 13 48% lower fresh weight compared to the untreated control.
Rigid ryegrass dry weight was recorded at 34% and 37% of control when PA4 and EO3 treatments were applied, respectively.
Manuka oil provided the highest efficacy of all the experimental treatments against rigid ryegrass.
In the final measurement, carried out at 7 DAT, a 47% biomass reduction was recorded for PA3 as compared to the control.
Increased was the efficacy of PA2 and pine oil application since rigid ryegrass dry weight was recorded at 30% and 33% of control.
The mixture of lemongrass oil and pelargonic acid resulted in 77% lower dry weight in comparison to the value recorded for the control.
Biomass reduction reached the level of 90% as compared to the control in the case of manuka oil and similar was the efficacy of manuka oil and pelargonic acid mixture (Table 3).
Table 3. Dry weight and height of L. rigidum plants as affected by the application of the natural herbicides at 1, 3 and 7 days after treatment (DAT).
Dry weight and height values of L. rigidum plants was expressed as % of control.
Dry Weight (%) of Control Height (%) of Control Treatment 1 DAT 3 DAT 7 DAT 1 DAT 3 DAT 7 DAT PA1 46 b 42 ab 41 b 44 cb 43 b 40 ab PA2 34 d 29 cde 30 cd 38 bcd 27 def 28 cd PA3 59 a 52 a 53 a 63 a 54 a 51 a PA4 41 bcd 37 bcd 37 b 42 bcd 33 cde 35 bc EO1 41 bcd 27 de 10 e 45 b 28 cdef 8 e EO2 42 bc 39 bc 40 b 40 bcd 36 bc 38 bc EO3 38 cd 34 bcd 33 cd 37 de 35 bcd 36 bc M1 37 cd 22 e 6 e 36 e 24 f 7 e M2 36 cd 29 cde 23 d 40 bcd 26 ef 21 d LSD (0.05) 8 10 11 7 8 11 p value ** ** *** *** *** ** Different letters in the same column for L. rigidum dry weight and height, separately, indicate the significant differences between the means for each treatment at a = 5% significance level. **, *** = significant at 0.05, 0.01 and 0.001, respectively.
At 1 DAT, height of rigid ryegrass was recorded at 63% of the untreated control when PA3 was applied.
Lemongrass essential oil (EO2), PA2 and PA4 treatments resulted in 58–62% lower height as compared to the control.
The efficacy of the manuka oil and pelargonic acid mixture as well as the efficacy of pine oil was similar and slightly increased in comparison to the three treatments mentioned above.
In the second measurement carried out at 3 DAT, rigid ryegrass height was recorded at 43% of control in the case of PA1 whereas the adoption of PA2, PA4 and EO1 resulted in 67–73% in comparison to the control.
Similar was the efficacy of the two mixtures used since height reduction reached the level of 74–76% as compared to the value recorded for the untreated plants and these two treatments were the most efficient against rigid ryegrass. In the final measurement carried out at 7 DAT, the efficacy of PA3 was similar to the two previous measurements whereas the application of lemongrass and pine oil resulted in 62–64% lower plant height as compared to the control. In addition, PA2 was even more effective since plant height was recorded at 28% of control in the case of this treatment.
Manuka oil, as well as its mixture with pelargonic acid, were by far the most effective treatments since rigid ryegrass plant height was reduced by 92–93% (Table 3).
3.2. Effects of the Experimental Treatments on A. sterilis Dry Weight and Height Regarding sterile oat, at 1 DAT it was observed that PA3 reduced dry weight by 52% as compared to the control. The efficacy of PA2 treatment was significantly higher than PA3. Essential oils derived from manuka, lemongrass and pine showed similar efficacy.
The mixture of manuka oil and pelargonic acid (M1) was by approximately 6% more effective than the mixture of lemongrass oil and pelargonic acid (M2).
At 3 DAT, it was noticed that sterile oat dry weight was recorded at 44% of control when PA3 treatment was applied while the corresponding value recorded under pine oil application was Agronomy 2020, 10, 1687 7 of 13 recorded at 35% of control.
PA1 and PA4 treatments were more effective than PA3 treatment whereas lemongrass and manuka oils were characterized by similar efficacy.
The most effective treatment was the mixture of manuka oil and pelargonic acid given that its application reduced dry weight by 82% as compared to the control. The results of the measurement carried out at 7 DAT clarified that PA3 was the least efficient treatment against sterile oat since weed biomass was recorded at 41% of control whereas the corresponding values recorded for PA4, PA1, EO2 and EO3 treatments ranged between 31 and 33% of control. The efficacy of the lemongrass oil and pelargonic acid mixture was significantly higher.
Manuka oil resulted in a biomass reduction higher than 90% whereas the manuka oil and pelargonic acid mixture reduced weed biomass by 96% as compared to the value recorded for the untreated plants (Table 4). Table 4. Dry weight and height of A. sterilis plants as affected by the application of the natural herbicides at 1, 3 and 7 days after treatment (DAT). Dry weight and height values of A. sterilis plants was expressed as % of control. Dry Weight (%) of Control Height (%) of Control Treatment 1 DAT 3 DAT 1 DAT 3 DAT 1 DAT 3 DAT PA1 36 bcd 33 bc 33 ab 38 bc 36 b 35 ab PA2 27 e 24 de 23 bc 29 c 27 cde 24 cd PA3 48 a 44 a 41 a 53 a 46 a 42 a PA4 33 cde 30 bcd 31 ab 36 bc 33 bc 32 bc EO1 42 ab 28 bcd 7 de 44 ab 31 bcd 12 ef EO2 36 bcd 31 bcd 32 ab 37 bc 34 bc 34 ab EO3 39 bc 35 b 32 ab 42 b 37 b 35 ab M1 28 de 18 e 4 e 30 c 20 e 8 f M2 34 bcde 25 cde 17 cd 36 bc 25 de 19 de LSD (0.05) 9 8 11 9 7 9 p value * ** *** * ** *** Different letters in the same column for A. sterilis dry weight and height, separately, indicate the significant differences between the means for each treatment at a = 5% significance level. *, **, *** = significant at 0.05, 0.01 and 0.001, respectively.
Sterile oat height was recorded at 53% of control when PA3 was applied as it was observed at 1 DAT.
Sterile oat height ranged between 36% and 38% of control for PA4 and PA1 while almost the same plant height reduction was attributed to lemongrass essential oil application.
Height reduction was estimated at 30% as compared to the value recorded for the untreated plants in the case of manuka oil and pelargonic acid mixture.
This mixture was also approximately 6% more effective than the lemongrass oil and pelargonic acid mixture.
At 3 DAT, PA3 remained the least effective of all the studied treatments given that its efficacy was lower than the corresponding of EO3, PA1 and PA4 treatments.
The plant height values observed when manuka and lemongrass essential oils were applied were similar.
PA2 application resulted in 73% lower sterile oat height as compared to the control.
The efficacy of lemongrass oil and pelargonic acid mixture was similar, whereas mixing manuka oil and pelargonic acid was the most effective treatment of all against sterile oat.
The final measurement carried out at 7 DAT confirmed that PA3 was the least effective treatment of all, while lemongrass and pine essential oils were more efficient than PA3 treatment. Mixing lemongrass oil with pelargonic acid was more effective than the treatments mentioned above.
Manuka oil application was even more effective whereas its mixture with pelargonic acid resulted in the greatest plant height reduction which was recorded at 92% as compared to the control (Table 4). 3.3. Effects of the Experimental Treatments on G. aparine Dry Weight and Height In general, all the experimental treatments were more effective against cleaver than against the grass weeds studied. In particular, manuka and lemongrass essential oils provided a 67–70% biomass reduction in comparison to the control whereas biomass reduction for the two mixtures ranged between Agronomy 2020, 10, 1687 8 of 13 76% and 78% in comparison to the control as observed in the measurement carried out 24 h after treatment. The efficacy of all the pelargonic acid formulations was remarkable. At 3 DAT, it was observed that pine oil was 7% and 11% more effective than manuka and lemongrass essential oils, respectively, and the efficacy of the two mixtures was similar. PA3 treatment reduced weed biomass by 90%, whereas the application of PA2 treatment almost eliminated cleaver plants.
At 7 DAT, the efficacy of lemongrass and pine oils was similar, whereas manuka oil was characterized by increased efficacy (up to 92%).
PA4 and PA1 treatments resulted in a 96–97% dry weight reduction than the corresponding value recorded for the untreated plants. Weed dry weight was recorded at 6% of control in the case of lemongrass oil and pelargonic acid mixture whereas PA2 and M1 treatments completely eliminated cleaver plants (Table 5).
Table 5. Dry weight and height of G. aparine plants as affected by the application of the natural herbicides at 1, 3 and 7 days after treatment (DAT).
Dry weight and height values of G. aparine plants is expressed as % of control.
Dry Weight (%) of Control Height (%) of Control Treatment 1 DAT 3 DAT 1 DAT 3 DAT 1 DAT 3 DAT PA1 12 def 5 cd 4 d 14 def 6 cd 6 cd PA2 5 f 2 d 0 d 8 f 4 d 0 d PA3 17 cde 10 bc 8 bc 20 cde 12 bc 11 bc PA4 10 ef 5 cd 3 d 13 ef 6 cd 5 cd EO1 33 a 23 a 8 bc 36 a 27 a 11 bc EO2 30 ab 27 a 25 a 33 ab 29 a 27 a EO3 19 cd 16 b 14 b 21 cd 19 b 18 b M1 22 c 12 b 0 d 25 c 13 bc 0 d M2 24 bc 15 b 6 bc 26 bc 16 b 8 cd LSD (0.05) 8 6 9 8 7 9 p value *** *** ** *** *** ** Different letters in the same column for G. aparine dry weight and height, separately, indicate the significant differences between the means for each treatment at a = 5% significance level. **, *** = significant at 0.05, 0.01 and 0.001, respectively. Cleaver height was by 64 and 67% lower compared to the control when manuka and lemongrass oils were applied, respectively, as noticed at 1 DAT. The efficacy of manuka oil and pelargonic acid were by 11% higher than the corresponding value of manuka oil alone and even higher was the efficacy of PA4 and PA1. PA2 treatment was the most effective of all the treatments studied, since its application reduced weed height by approximately 92% as compared to the control.
The results of the second measurement revealed that cleaver height was recorded at 27% and 29% of control when manuka and lemongrass essential oils were applied, respectively.
The mixture of lemongrass oil and pelargonic acid was characterized by similar efficacy to pine oil whereas PA3 treatment reduced plant height by almost 88% as compared to the control.
At 7 DAT, it was noticed that lemongrass oil application was the least effective treatment against cleaver whereas pine oil was by 9% more effective. Cleaver height was only recorded at 5%, 6% and 8% of control when PA4, PA1 and M2 treatments were applied, while either manuka oil and pelargonic acid mixture or PA2 treatment completely eliminated cleaver plants (Table 5). 4. Discussion The results of the current study revealed the different efficacy of the four pelargonic acid products against the different weed species.
In most cases, broadleaf weeds like cleaver were more susceptible than grass species, while the formulations of increased pelargonic acid concentration (e.g., PA2) were significantly more effective. Our findings are in contrast with the corresponding of Muñoz et al. [8] who noticed that all the pelargonic acid-based herbicides managed to completely eliminate Avena fatua (L.) plants at 3 DAT whereas there were no significant differences regarding the efficacy of the different Agronomy 2020, 10, 1687 9 of 13 pelargonic acid formulations. The insufficient control of rigid ryegrass and sterile oat when the low-concentration formulation of pelargonic acid was applied is in agreement with the findings of a previous study in which the application of pelargonic acid at the concentration of 2% (v/v) provided only 20% total weed control [14]. However, the same authors noticed that the same treatment controlled broadleaf weeds such as velvetleaf (Abutilon theophrastii Medic.) by only 31%. In our study, cleaver was adequately controlled by the majority of the pelargonic acid-based treatments even 24 h after treatment.
Moreover, it was noticed that at 7 DAT, all the treatments did reduce cleaver dry biomass and plant height sufficiently.
The possible effects of climatic conditions on the efficacy and the overall results is something that should be further studied.
In our case, although weather conditions before and at spraying seemed favorable for the pot experiments, pelargonic acid products did not show remarkable efficacy against the two grass weed species. This outcome might be attributed to the air temperature at spraying time. The hypothesis of Krauss et al. [37] regarding the impact of weather conditions on the efficacy of pelargonic acid products was similar.
In any case, this is an objective that should be systematically evaluated in future studies.
In addition, there is evidence that various weed species can develop new shoots and recover after pelargonic acid application.
Hence, another objective for a future experiment would be to find out the level of weed regrowth that emerges over a longer term than 7 DAT for a wider range of weed species.
In fact, the natural substances are not translocated systemically in the plants and they cannot provide long-term weed control for most species.
However, it has already been reported that sufficient weed control might be achieved with repeated treatments.
Moreover, it was obvious that the different weed species’ responses to the application of the natural herbicides showed variability.
This emphasizes the importance of further multifactor experiments towards the comparison of the effects of such experimental treatments between numerous weed species.
The efficacy of pelargonic acid-based herbicides under real field conditions is an unexplored area of great interest.
There are not many studies evaluating the level of weed control in the field and defining the crops that can be favored by the adoption of such weed control practices.
However, there were interesting results in a more recent study carried out in Greece by Kanatas et al. in which pelargonic acid along with maleic hydrazide was applied for non-selective weed control before sowing soybean crop in a stale seedbed. In particular, it was revealed that stale seedbed combined with pelargonic acid application reduced annual weeds’ density by 95% as compared to normal seedbed, indicating that such pelargonic acid-based herbicides can be equally effective to glyphosate against annual weeds in a stale seedbed where a crop is about to be established and reap the benefits of pre-sowing weed elimination [19].
On one hand, it seems that integrated weed management strategies, including cultural practices such as the stale seedbed preparation, could maximize the herbicidal potential of pelargonic acid under real field conditions.
Consequently, the level of weed control as assured by pelargonic acid-based herbicides could be sufficient if a vigorous and competitive crop is about to be sown.
It has been reported recently in Greece that the competitiveness of barley (Hordeum vulgare L.) against troublesome weeds such as rigid ryegrass of sterile oat can be promoted if such organic weed control practices are applied before crop sowing [40].
On the other hand, after the nonanoic acid application, there was no weed cover reduction at one and two days after treatment in both experimental sites as well as repetitions in the field experiments of Martelloni et al. , where a treatment similar to PA-4 treatment was applied for weed control.
The explanation suggested for this outcome was that weeds were in unsuitable growth stage for the natural herbicide to have an effect.
Previous research has reported that nonanoic acid needs to be applied to very young or small plants for acceptable weed control, and repeated applications are suggested .
However, in the current experiment, it was observed that increasing pelargonic acid concentration in a natural herbicide product can result in more efficient control for grasses and barely elimination of broadleaves.
This finding is in agreement with the ones reported by Rowley et al., who observed an intermediate reduction in weed ground coverage, density, and dry weed biomass due to the higher rate of nonanoic acid used (39 L a.i. ha−1 ). Other authors found an intermediate reduction in Japanese stiltgrass (Microstegium vimineum Trin.)
Agronomy 2020, 10, 1687 10 of 13 ground coverage as compared to their control treatment due to the pelargonic acid application at a rate of 11.8 kg a.i. ha−1 and 5% (v/v) concentration [44]. Concerning the potential role of maleic hydrazide, this was not statistically significant in the present study, probably due to the measurements being only for 7 days and not on a long-term basis.
However, the use of products containing pelargonic acid along with maleic hydrazide is a promising tactic.
An explanation might be given by the fact that maleic hydrazide has systemic activity and can be translocated in the meristematic tissues, with mobility in both phloem and xylem.
Although its mode of action is not totally clear, it can be used effectively for the control of troublesome parasitic weed species belonging to Orobanche spp..
This is quite important, given that a factor restricting the herbicidal potential of pelargonic acid is the absence of systemic activity, with maleic hydrazide reducing weed regrowth and ensuring a long-term control.
The findings of the present study also revealed that manuka oil is a possible solution for dealing with the challenge of increasing the systemic activity of natural herbicides.
Even without being mixed with pelargonic acid, manuka oil showed increased efficacy against all the weeds as compared to the other essential oils and pelargonic acid treatments. In the study of Dayan et al. [32], it was noticed that manuka oil and its main active ingredient, leptospermone, were stable in soil for up to 7 d and had half-lives of 18 and 15 days after treatment, respectively. Such findings indicate the systemic activity of manuka oil and also that it can be a useful tool addressing many the restricting factors related to the use of natural herbicides. Dayan et al. [32] also recorded 68%, 57%, 93%, 88%, 73% and 50% lower biomass for pigweed (Amaranthus retroflexus L.), velvetleaf, field bindweed (Convolvulus arvensis L.), hemp sesbania [Sesbania exaltata (Raf.) Rydb. ex A.W. Hill], large crabgrass (Digitaria sanguinalis L.) and barnyardgrass (Echinochloa crus-galli L. P. Beauv.) as compared to the control, respectively, when a mixture with lemongrass essential oil was mixed with manuka oil and applied to the targeted weed species mentioned above. Pine and lemongrass essential oils provided a biomass reduction for rigid ryegrass and sterile oat ranging between 60% and 70% whereas they were more effective against the broad leaf species G. aparine.
In the study of Young [45], pine oil controlled hairy vetch (Vicia villosa Roth), broadleaf filaree (Erodium botrys (Cav.) Bertol.), and hare barley (Hordeum murinum L.) at least 83%, but yellow starthistle (Centaurea solstitialis L.), soft brome (Bromus hordeaceus L.), control never surpassed the level of 85%.
In the greenhouse experiment of Poonpaiboonpipat et al. [46], it was noted that lemongrass essential oil at concentrations of 1.25%, 2.5%, 5% and 10% (v/v) was phytotoxic against barnyard grass, since leaf wilt symptoms were observed at just 6 h after treatment.
The same authors also noticed that chlorophyll a, b and carotenoid content decreased under increased concentrations of the essential oil, indicating that lemongrass essential oil interferes with the weeds’ photosynthetic metabolism [46].
Although the herbicidal potential of such essential oils does exist, many studies have concluded that there are limitations since the essential oils act as contact herbicides with no systemic activity [9,30,32,45,46].
They generally disrupt the cuticular layer of the foliage, which results in the rapid desiccation or burn-down of young tissues.
However, lateral meristems tend to recover, and additional applications of essential oils are necessary to control regrowth.
Essential oils must be applied at high concentrations to convey 50 to 500 L of active ingredient per hectare [30].
The limitations of applying either lemongrass or pine essential oils for weed control are similar to those mainly observed in the case of pelargonic acid-based herbicides.
Manuka oil differs from other essential oils in that it contains large amounts of several natural b-triketones, including leptospermone, which enable this oil to have systemic activity [47].
One of the most important findings of the present study was the satisfactory control of all the targeted weed species in the case where the mixture of manuka oil and pelargonic acid was applied. This synergy resulted in improvement of overall weed control, compared to the cases in which pelargonic acid formulations, lemongrass and pine essential oils were used alone.
This is one of the key findings of this study, and provides vital information for improving weed control in terms of either organic or sustainable agriculture.
The findings of Coleman and Penner [14] were similar, finding that the addition of diammonium succinate and succinic acid improved the efficacy of a pelargonic acid formulation up to 200%, whereas l-Lactic acid and glycolic Agronomy 2020, 10, 1687 11 of 13 acid enhanced the efficacy of pelargonic acid formulations on velvetleaf and common lambsquarters (Chenopodium album L.) up to 138% even under real field conditions.
5. Conclusions To date, no studies have evaluated the herbicidal potential of several pelargonic acid products, essential oils and mixtures of natural herbicides against major weed species in Greece.
The findings of the present study revealed that selecting natural products with high concentrations of pelargonic acids can increase the control levels of grass weeds.
However, in the case of broadleaf weeds, it seems that the application of natural products might lead to sufficient weed control even when products of lower pelargonic acid concentration are applied. The results of the current study also validated that lemongrass and pine oil act as contact burn-down herbicides, whereas manuka oil showed a systemic activity.
The synergy between manuka oil and pelargonic acid is reported for the first time and is one of the key findings of the present study.
This unique essential oil might deal with the lack of systemic activity associated with pelargonic acid and further experiments are in progress by our team.
Further research is needed to evaluate more natural substances and combinations in order to optimize the use of natural herbicides as well as natural herbicides’ mixtures in weed management strategies in both organic and sustainable agriculture systems and also under different soil and climatic conditions.
Pelargonic Acid is a naturally-occurring saturated fatty acid with nine carbon atoms. The ammonium salt form of pelargonic acid is used as an herbicide.
Pelargonic Acid works by stripping the waxy cuticle of the plant, causing cell disruption, cell leakage, and death by desiccation.
Pelargonic acid is a C9 straight-chain saturated fatty acid which occurs naturally as esters of the oil of pelargonium.
Pelargonic acid has antifungal properties, and is also used as a herbicide as well as in the preparation of plasticisers and lacquers.
Pelargonic acid has a role as an antifeedant, a plant metabolite, a Daphnia magna metabolite and an algal metabolite.
Pelargonic acid is a straight-chain saturated fatty acid and a medium-chain fatty acid. It is a conjugate acid of a nonanoate. Nonanoic acid derives from a hydride of a nonane.
γ-nonanolactone has functional parent nonanoic acid
(8R)-8-hydroxynonanoic acid has functional parent nonanoic acid
(R)-2-hydroxynonanoic acid has functional parent nonanoic acid
1-nonanoyl-2-pentadecanoyl-sn-glycero-3-phosphocholine has functional parent nonanoic acid
1-octadecanoyl-2-nonanoyl-sn-glycero-3-phosphocholine has functional parent nonanoic acid
2-hydroxynonanoic acid has functional parent nonanoic acid
2-oxononanoic acid has functional parent nonanoic acid
7,8-diaminononanoic acid has functional parent nonanoic acid
8-amino-7-oxononanoic acid has functional parent nonanoic acid
9-(methylsulfinyl)nonamide has functional parent nonanoic acid
9-(methylsulfinyl)nonanoic acid has functional parent nonanoic acid
9-aminononanoic acid has functional parent nonanoic acid
9-hydroxynonanoic acid has functional parent nonanoic acid
9-oxononanoic acid has functional parent nonanoic acid
N-nonanoylglycine has functional parent nonanoic acid
ethyl nonanoate has functional parent nonanoic acid
hexadecafluorononanoic acid has functional parent nonanoic acid
methyl nonanoate has functional parent nonanoic acid
nonanal has functional parent nonanoic acid
nonanoyl-CoA has functional parent nonanoic acid
perfluorononanoic acid has functional parent nonanoic acid
trimethylsilyl nonanoate has functional parent nonanoic acid
nonanoate is conjugate base of nonanoic acid
nonanoyl group is substituent group from nonanoic acid
acid nonanoic (ro)
Acid nonanoic, acid pelargonic (ro)
acide nonanoique (fr)
Acide nonanoïque, acide pélargonique (fr)
acido nonanoico (it)
Acido nonanoico, acido pelargonico (it)
Aċidu nonanoiku, Aċidu pelargoniku (mt)
kwas nonanowy (pl)
Kwas nonanowy, kwas pelargonowy (pl)
kwas pelargonowy (pl)
Kyselina nonanová, kyselina pelargonová (cs)
kyselina nonánová (sk)
Kyselina nonánová (kyselina pelargónová) (sk)
Nonaanhape (et)
Nonaanhape, pelargoonhape (et)
Nonaanihappo (fi)
Nonaanihappo (pelargonihappo) (fi)
nonaanzuur (nl)
Nonaanzuur, pelar-goonzuur (nl)
nonano rūgštis (lt)
Nonano rūgštis, pelargono rūgštis (lt)
Nonanoic acid, Pelargonic acid (no)
nonanojska kislina (sl)
Nonanojska kislina, pelargonska kislina (sl)
nonanonska kiselina (hr)
nonanová kyselina (cs)
Nonanska kiselina, pelargonična kiselina (hr)
nonansyra (sv)
Nonansyra, pelargonsyra (sv)
nonansyre (da)
nonansyre (no)
Nonansyre og pelargonsyre (da)
Nonansäure (de)
Nonansäure, Pelargonsäure (de)
nonánsav (hu)
Nonánsav, pelargonsav (hu)
Nonānskābe (lv)
nonānskābe (lv)
ácido nonanoico (es)
Ácido nonanoico, ácido pelargónico (es)
ácido nonanóico (pt)
Ácido nonanóico, Ácido pelargónico (pt)
Εννεανικό οξύ (πελαργονικό οξύ) (el)
εννεανοϊκό οξύ (el)
нонанова киселина (bg)
Нонанова киселина, пеларгонова киселина (bg)
CAS names: Nonanoic acid
IUPAC names
Acid C9, Pelargonic acid
NONANOIC ACID
Nonanoic Acid
Nonanoic acid
nonanoic acid
nonanová kyselina
Nonansäure
Pelargonic acid
Pelargonic and realted fatty acids
Trade names
Acido Pelargónico
Pelargonic acid
Prifrac 2913
Prifrac 2914
Prifrac 2915
Synonyms
1-nonanoic acid
1752351 [Beilstein]
267-013-3 [EINECS]
506-25-2 [RN]
Acid C9
Acide nonanoïque [French] [ACD/IUPAC Name]
n-nonanoic acid
n-Nonylic acid
Nonanoic acid [ACD/Index Name] [ACD/IUPAC Name]
Nonansäure [German] [ACD/IUPAC Name]
n-Pelargonic acid
Pelargonic Acid
RA6650000
Pergonic acid
130348-94-6 [RN]
134646-27-8 [RN]
1-OCTANECARBOXYLIC ACID
4-02-00-01018 (Beilstein Handbook Reference) [Beilstein]
Cirrasol 185A
EINECS 203-931-2
EINECS 273-086-2
Emery 1203
Emery'S L-114
http://www.hmdb.ca/metabolites/HMDB0000847
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:29019
Jsp000917
KNA
KZH
MLS001066339
NCGC00164328-01
n-Nonanoic-9,9,9-d3 acid
n-Nonoic acid
Nonansaeure
noncarboxylic acid
nonoic acid
nonylic acid
Pelargic acid
pelargon
Pelargon [Russian]
Pelargon [Russian]
Pelargonic Acid 1202
Pelargonsaeure
SMR000112203
VS-08541
WLN: QV8
Synonym Source
1-Nonanoate
1-Nonanoic acid ChEBI
1-Octanecarboxylate
1-Octanecarboxylic acid
CH3-[CH2]7-COOH
Cirrasol 185a
Emery 1202
Emery'S L-114
Emfac 1202
FA(9:0)
Product name
Nonanoic acid (Pelargonic acid), Fatty acid
Description
Fatty acid.
Alternative names
Pelargonic acid
Biological description
Potent antifungal agent (IC50 = 50 μM against Trichophyton mentagrophytes). Inhibits spore germination and mycelial growth of pathogenic fungus. Active in vivo.
Nonanoic acid is now used relatively extensively as an herbicide in the home garden. A recent evaluation of an acute eye irritation study indicated moderate eye irritation following exposure to a product formulation containing 1.8% nonanoic acid.
Applications
Nonanoic acid is used in the preparation of plasticizers and lacquers. It is commonly used in conjunction with glyphosate, for a quick burn-down effect in the control of weeds in turfgrass.
Investigation of antimicrobial activities of nonanoic acid derivatives
January 2006Fresenius Environmental Bulletin 15(2):141-143
Abstract and Figures
In a search for promising antimicrobial compounds, seven derivatives of methyl-branched n-nonanoic acid (MNA) at positions 2, 3, 4, 5, 6, 7, and 8 have been synthesized, and antimicrobial activity is described. Anti-microbial activities were determined by using disk diffusion tests and expressed as MIC values for the n-nonanoic acid using the microdilution broth method in vitro against Bacillus subtilis, Mycobacterium smegmatis, Sarcina lutea, Escherichia coli, Salmonella typhimurium and Streptomyces nojiriensis for bacteria, and Candida utilis for fungi, and compared with Penicillin G and Polymyxin B. All compounds exhibit varied antimicrobial activity against Gram-positive bacteria, but remarkable inhibitory effects were observed against C. utilis and S. lutea in two compounds (2-MNA and 5-MNA). Interestingly, only 4-MNA, 7-MNA and 8-MNA possess activity against Streptomyces.
Synonyms
Pelargonic acid; 1-Octanecarboxylic acid; Cirrasol 185A; Cirrasol 185a; Emfac 1202; Hexacid C-9; Nonoic acid; Nonylic acid; Pelargic acid; Pelargon [Russian]; n-Nonanoic acid; n-Nonoic acid; n-Nonylic acid; [ChemIDplus]
Sources/Uses
Naturally occurs as an ester in oil of pelargonium; [Merck Index] Found in several essential oils; Used in lacquers, pharmaceuticals, plastics, and in esters for turbojet lubricants; Also used as a flavor and fragrance, flotation agent, gasoline additive, herbicide, blossom thinner for apple and pear trees, sanitizer, and to peel fruits and vegetables; [HSDB] Used to make peroxides and greases, as a catalyst for alkyd resins, in insect attractants, and as a topical bactericide and fungicide medication; [CHEMINFO]
Comments
Category of C7-C9 aliphatic aldehydes and carboxylic acids: Members and supporting chemicals demonstrate low acute toxicity by oral, dermal, and inhalation exposures; toxicity in repeated-dose studies only at relatively high levels; no evidence of reproductive toxicity, developmental toxicity, or mutagenicity; [EPA ChAMP: Hazard Characterization] Highly irritating; [Merck Index] A strong skin irritant; [Hawley] A skin and eye irritant; [HSDB] May cause permanent eye damage, including blindness; [CHEMINFO] Safe when used as a flavoring agent in food; [JECFA] A corrosive substance that can cause injury to the skin, eyes, and respiratory tract; [MSDSonline]
Use of nonanoic acid as an antimicrobial agent, in particular an antifungal agent
Abstract
The invention relates to the use of nonanoic acid as an antimicrobial, in particular antifungal, agent or additive, in particular in or for foods, such as dairy products or fruit juices.
A particular aspect of the invention comprises the use of nonanoic acid i a cheese coating.
The invention also relates to a cheese coating in which nonanoic acid has been incorporated as antifungal agent; a cheese that has been provided with such a coating; and a nonanoic acid-containing composition for applying such a coating.
The nonanoic acid is used in particular on or close to the surface of the food, or uniformly distributed through the food, in an amount of 10 - 10,000 ppm, in particular 100 - 1,000 ppm. The nonanoic acid can furthermore be used as an antimicrobial agent for treating substrates or surfaces, in particular substrates or surfaces that come into contact with foods; for protecting foods, cut flowers and bulbs during transport and/or during storage; in disinfectants and cleaning agents; to protect or treat wood; in cosmetics or skin care products; and in pharmaceutical compositions to prevent and treat fungal infections and yeast infections , such as Candida.
Use of nonanoic acid as an antimicrobial agent, in particular an antifungal agent
The present invention relates to the use of nonanoic acid as an antimicrobial agent, in particular an antifungal agent.
More particularly, the invention relates to the use of nonanoic acid as an antimicrobial agent, in particular an antifungal agent, in foods and in particular in dairy products such as cheese and products based on fruit, such as fruit juices.
The invention furthermore relates to foods which contain nonanoic acid as an antimicrobial agent.
Particular aspects of the invention lie in the use of nonanoic acid in (solutions or suspensions for) cheese coatings, in the nonanoic acid-containing cheese coatings thus obtained and in the cheeses coated with these nonanoic acid-containing coatings.
The use of the nonanoic acid in food products is known.
For instance, it is used as a synthetic flavouring in, for example, non-alcoholic drinks, ice cream, confectionery, gelatine, milk puddings and bakery products.
US Patent 2 154 449 describes the antifungal properties of C3 - CI2 carboxylic acids and salts thereof, in particular the incorporation of calcium propionate in bread dough in order to prevent the formation of mould on bread.
European Patent Application EP 0 244 144 A 1 teaches the addition of glyceryl fatty acid esters in combination with one or more C6.C,8 carboxylic acids as preservatives to, inter alia, food compositions.
International application WO 96/29895 describes a method for improving the shelf/storage life of perishable products by treating surfaces, equipment and materials, which come into contact with the products during the processing thereof, with an antimicrobial aromatic compound.
WO 96/29895 states that fatty acids, including nonanoic acid, can also be used in combination with the aromatic compound.
International application WO 92/19104 teaches the use of C7 - C20 carboxylic acids, including nonanoic acid, for controlling infections in plants caused by bacteria and moulds.
European Patent Application EP 0 022 289 relates to the incorporation of C3 - C, , carboxylic acids in polymers for the production of medical instruments, such as catheters.
European Patent Application EP 0 465 423 describes antimicrobial pharmaceutical preparations containing C4 - C,4 carboxylic acids.
US Patent 4 406 884 describes antimicrobial pharmaceutical preparations for topical use which contain C5 - C,2 carboxylic acids.
US Patent 3 931 413 teaches the treatment of plants with C6 - C,8 carboxylic acids to combat infections by moulds which overwinter in the buds of the plants.
Nonanoic acid is also used in some meat products to adjust the acidity.
For instance, US Patent 4 495 208 describes a dog or cat food with good storage/shelf life which has a high moisture content (Aw > 0.9 and a water content of 50 - 80 %) that contains 4 -15 % (m/m) fructose, 0.3 - 3.0 % (m/m) of an edible organic acid, sufficient inorganic acid to obtain a pH in the range of 3.5 - 5.8 and an antifungal agent.
The organic acid is preferably chosen from heptanoic acid, octanoic acid, nonanoic acid or a combination thereof.
In the animal feed according to US Patent 4 495 208 the edible organic acid is always present alongside a sugar (fructose) and an antifungal agent (antimycotic) known per se, such as sorbic acid and/or the salts thereof.
It is stated that the combination of these three constituents in the indicated amounts gives a synergistic bactericidal action.
US Patent 3 985 904 describes a food based on meat which has a high moisture content and is suitable for human consumption or as an animal feed.
This food has a moisture content of at least approximately 50 % (m m) and a water activity A,,, of at least approximately 0.90 and contains more than 50 % (m/m) of a ground, boiled, protein-like chicken, fish or meat material. 1 - 35 % (m m) of a gelatine-like filler based on starch, between 1.7 and 3.8 % of an edible, non-toxic acid and an effective amount of an antifungal agent.
The edible organic acid is incorporated in this food in an amount which is sufficient to bring the pH of the food to a value in the range from 3.9 to 5.5.
Although US-A 3 985 904 mentions various suitable edible acids in column 6, nonanoic acid is not explicitly mentioned here.
According to US-A 3 985 904, the antifungal agent is chosen from benzoates, propionates and sorbate salts.
EP-A 0 876 768 describes the use of fatty acid monoesters of polyglycerol to improve the storage/shelf life of foods.
Here the fatty acid radicals can be chosen from caproic acid, caprylic acid, lauric acid or myristic acid.
The use of nonanoic acid in herbicidal compositions for agricultural use is described, inter alia, in US Patents 5 098 467, 5 035 741, 5 106 410 and 5 975 4110. US Patents 4 820 438, 5 330 769 and 5 391 379 describe the use of nonanoic acid in soap and cleaning agents.
None of the above literature citations describes or suggests unambiguously that nonanoic acid can be safely incorporated in foods and/or can be used on foods in order to inhibit the growth of bacteria, moulds and yeasts. In particular, none of these literature citations teaches the dosage at which nonanoic acid can safely be used for this purpose.
Currently, natamycin is used as antifungal agent in cheese making.
This compound, which is also designated pimaricin or "antibiotic A5283" and is marketed under the trade names Delvocid® and Natamax® (inter alia), is a metabolic product of Streptomyces natalensis and S. chattanoogensis.
However, the use of natamycin has a number of disadvantages. For instance it is fairly expensive.
Moreover, it has been found that the mould Penicillium discolor is able to grow on (the surfaces of) cheeses treated with natamycin.
This is particularly disadvantageous in the cheese industry, since P. discolor is widespread in cheese warehouses.
It has now been found that nonanoic acid displays an antimicrobial action, in particular an antifungal action, especially when it is used in amounts which can suitably be incorporated in food products. More particularly, it has been found that nonanoic acid can advantageously be used as an antimicrobial agent, in particular antifungal (fungicidal) agent, in dairy products such as cheese and products based on fruit, such as fruit juices.
The antimicrobial action of nonanoic acid found according to the invention is partly surprising because it is known that some types of mould (such as Aspergillus niger, Synchephalastrum racemosus, Geotrichum candidum, Penicillium expansum, Rhizopus stolonifer and Mucor plombus) naturally produce nonanoic acid.
In addition, it has been found according to the invention that nonanoic acid is also able to inhibit the development of yeasts, which can likewise arise in cheese warehouses.
In a first aspect the invention therefore relates to the use of nonanoic acid (n-octane- 1 -carboxylic acid, pelargonic acid, n-nonylic acid) as an antimicrobial agent, in particular antifungal agent (additive) in or for foods and/or other products which have to be protected against perishing caused by microorganisms.
The invention also relates to the use of salts of nonanoic acid as an antimicrobial agent.
The invention further relates to foods which contain nonanoic acid as an antimicrobial agent, in particular antifungal agent.
The food can be any substance that is suitable for consumption by humans or animals, in particular for human consumption, and can be either a ready-to-eat food product or a constituent that can be incorporated in or processed to give a food product. The food or food product is in particular a product or substance that is susceptible to perishing caused by microorganisms, including bacteria, yeasts and in particular moulds (that is to say when no antimicrobial agent is added), such as, for example, a substance or product which will keep for between a few days and a few weeks (for example from 3 days to 3 weeks) under the customary conditions for storage of the product, such as a temperature in the range from room temperature (20 - 25 °C) down to refrigerator temperature (approximately 4 °C). However, the invention is not restricted to these.
In this context the nonanoic acid is used to inhibit microbial growth, in particular the formation of mould, and thus to extend the storage/shelf life.
For instance, microbial growth can be retarded by the use of nonanoic acid.
The degree of retardation will be dependent on, inter alia, the food, the nonanoic acid concentration, the conditions under which the food is stored (temperature, atmospheric humidity), the types of microorganisms to which the food is exposed and the degree of loading.
In the case of mould formation, the mould formation (i.e. the point in time at which the first growth of mould is discernible to the naked eye) will in general be delayed by at least one day, preferably at least 5 - 7 days, that is to say at the temperature at which foods are usually stored - usually room temperature (20 °C) or in the refrigerator (4 °C) - compared with the untreated food. For instance, in the case of cheese that was coated with a nonanoic acid-containing coating according to the invention the first discernible formation of mould was postponed from 60 to 67 days. In this context reference is made to Example 1 below, as well as the results given in Figure 1.
For the purposes of the invention, "inhibiting mould formation" and/or "antifungal" is preferably also understood to mean that the development of yeasts is (also) inhibited.
Moreover, it has been established according to the invention that nonanoic acid also has an antibacterial action, for example against bacteria which cause food to perish or otherwise reduce the quality thereof, and or against pathogens such as Listeria, Legionella, Salmonella and E.coli O157, Staphylococcus.
This inhibitory action of nonanoic acid on (the growth of) bacteria can also advantageously be employed in (the preparation of) fermented dairy products such as yoghurt.
This will be explained in more detail below. The food can be a solid, semi-solid or fluid food and can be a fermented or non- fermented food.
A few non-limiting examples of foods in which nonanoic acid can be used according to the invention as an antimicrobial agent, in particular antifungal agent, are: - ready-to-eat food products, including dough products such as pre-baked bread, noodles, pasta, soups and the like; fish and meat products such as sausage, and products based on vegetables or fruit, such as fruit juices and canned fruit or combinations of fruit (juices) with dairy products; flour; nuts and (dried) southern fruits; and also products such as pre-prepared meals, diet foods, complete foods and baby food; foods and constituents for further processing, such as mayonnaise, ketchup and similar sauces; jam, marmalade and similar fruit preparations; and the like. According to the invention nonanoic acid can also be used outside the food sector as an antimicrobial agent, in particular antifungal and/or antibacterial agent, and examples of this will be given below.
One example that is worthy of mention at this juncture is the use of nonanoic acid or a nonanoic acid-containing coating to improve the storage/shelf life of fruit such as oranges, lemons, grapefruit, apples, pears and also nuts and (dried) southern fruits, coffee, tea, tobacco and the like, in particular before or during transport and/or during long-term storage, for example in a warehouse or a fruit store (which may or may not be air- conditioned).
When used as an antifungal agent according to the invention, the nonanoic acid will be used in an amount effective for the inhibition of moulds, yeasts and bacteria, which as a rule will be between 1 and 10,000 mg nonanoic acid per kg food, in particular 10-1,000 mg nonanoic acid per kg food and more particularly 100-500 mg nonanoic acid per kg food.
Thus, for example, nonanoic acid can be used in yoghurt in an amount of approximately 200 milligram (mg) nonanoic acid per kilogram (kg) yoghurt.
The lower limit for the effective amount of nonanoic acid will preferably be chosen from the series 10, 25, 50 or 100 mg nonanoic acid per kg food, whilst the upper limit is preferably chosen from the series 10,000, 5,000, 2,500, or 1,000 mg nonanoic acid per kg food.
Preferably, these amounts are based on the water content of the food. Thus, in the case of a food having a water content of 80 %, 80 % of the abovementioned amounts of nonanoic acid can also be added per kg food. The precise amount of nonanoic acid will, however, be dependent on the intended food and the way in which the nonanoic acid is used in the food.
Thus, the nonanoic acid can be uniformly distributed throughout the entire food but, for example - especially in the case of solid or semi-solid foods - can also be present essentially only on or near the surface of the food, for example in the form of a nonanoic acid-containing antimicrobial, in particular antifungal, coating or surface layer, or as a result of treatment of the surface of the food with nonanoic acid. In these latter cases the concentration of nonanoic acid, based on the complete food, can be low (that is to say lower than the amounts indicated above), provided that sufficient nonanoic acid is present at or close to the surface in order to achieve the desired antimicrobial, in particular antifungal, action.
In general the presence of nonanoic acid in amounts of 10 - 10,000 ppm, in particular 100 - 2,000 ppm - i.e. locally or uniformly throughout the entire food - will be adequate to obtain the desired antimicrobial, in particular antifungal, action. The same concentrations of nonanoic acid - i.e. locally or uniformly throughout the entire food - will as a rule be sufficient to inhibit and/or to prevent the growth of yeast and/or of bacteria.
In a preferred aspect the food product is a dairy product, which in general is defined as a food based on milk or constituents of milk, in particular based on cows milk or constituents thereof. The dairy product is in particular a fermented dairy product that can be solid, semi- solid or fluid.
A few non-limiting examples are cheese, butter, cream, yoghurt or yoghurt products (for example yoghurt drinks, such as, for example, milk/fruit juice drinks), cottage cheese, kefir, milk puddings and the like.
The invention can also be employed in food products in which such dairy products have been incorporated/processed, such as sauces, pastries, desserts, foods (including complete food and baby food), snacks (for example containing cheese), meat products (such as ham in which proteins have been incorporated), powdered milk and coffee whiteners, and the like.
Use in cheese, and in particular in cheeses which have a low salt content (that is to say less than 4 %, in particular less than 3 %) and a high moisture content (that is to say 30 % or more, in particular 40 % or more) is to be particularly preferred. This can be carried out in particular by treating the surface of the cheese with nonanoic acid.
Thus, the invention can (also) be used with feta, cheese spread and similar products.
The fermented dairy product preferably has a pH of 3.5 to 5.5, for example in the range of 5.1 - 5.5 for cheese and of 3.9 - 4.4 for yoghurt.
Although it is not precluded that addition of nonanoic acid according to the invention makes some (usually minor) contribution to achieving this value, the final pH will as a rule be the result of the fermentation process and the buffer action possibly associated with this.
In another preferred embodiment the food product is a fruit juice or similar drink, such as, for example, products in which dairy products such as milk or yoghurt and fruit juices have been processed, which have a limited shelf-life.
The nonanoic acid can be used in a manner known per se for antimicrobial agents, in particular antifungal agents, that is to say by adding the nonanoic acid or a nonanoic acid- containing additive to the food or food product, or incorporating the nonanoic acid or a nonanoic acid-containing additive in the food or food product, during and/or after the preparation thereof. During this operation the nonanoic acid can be uniformly mixed or distributed through the food and/or used on the surface of the food, for example by spraying or brushing with nonanoic acid (for example in the form of an aqueous solution), by immersing (in particular cheese) in a solution of nonanoic acid or by applying a nonanoic acid-containing coating. For this operation it is possible to use, for example, an aqueous solution or suspension of nonanoic acid or another nonanoic acid-containing, preferably liquid, mixture, which contains 100 - 5,000 ppm, in particular 200 to 3,000 ppm nonanoic acid and which furthermore can contain all constituents known per se for solutions for applying a cheese coating, such as (the constituents of) synthetic coatings known per se (for example based on copolymers) and/or coatings based on foodstuffs.
For instance - in a 140 gram coating for a 12.8 kg cheese - the nonanoic acid concentration in the coating can be 5,000 ppm (which corresponds to 49.2 mg nonanoic acid per kg cheese), 1,000 ppm (which corresponds to 9.8 mg/kg cheese) or 100 ppm (which corresponds to 0.98 mg/kg cheese).
The nonanoic acid-containing cheese coating thus obtained, the cheeses which have been provided with such nonanoic acid-containing cheese coatings and the nonanoic acid- containing solutions which are used in this operation form further aspects of the invention.
In this context a further advantage of nonanoic acid is that it is also able to counteract and/or prevent too extensive development of the surface flora on the cheese (coating) - which can lead to the cheese rind being adversely affected - (this is in contrast to natamycin, that essentially is not able to exert any influence on bacterial growth).
As a rule the nonanoic acid will be used to replace the one or more antimicrobial, in particular antifungal, additives already used in a food known per se.
In addition, the nonanoic acid can advantageously be used in those foods for which the known antimicrobial agents are unsuitable or less suitable.
For such applications the use of nonanoic acid can form an alternative to the sterilisation treatments and/or similar antimicrobial treatment (that is to say other than the use of an antimicrobial additive) which are otherwise required.
Usually a single treatment of the food with nonanoic acid - such as the application of a nonanoic acid-containing coating - will be sufficient to obtain the desired antimicrobial action. However, repeated treatment of the food with nonanoic acid is not precluded.
According to the invention nonanoic acid is used in particular to replace natamycin, in particular in applications in the dairy and cheese industries. In this regard reference is made, for example, to the applications of natamycin which are described by J. Stark in E>e Ware(n) Chemicus, 27 (1997), 173-176.
According to the invention nonanoic acid is highly preferentially compatible with the food, that is to say the use of nonanoic acid according to the invention has no adverse effect on the flavour, odour, consistency, pH or other desired characteristics of the food, at least not during the time that the food has to be or can be kept or stored prior to end use or consumption.
As a rule this means that the food must be acid-resistant to a certain extent, that is to say at least must be able to withstand the pH that is obtained by the use of the nonanoic acid in the abovementioned amounts. In the event of possible problems with the compatibility, the use of a separate nonanoic acid-containing coating can offer a solution.
The food can furthermore contain all other additives known per se for the food, provided that these are compatible with nonanoic acid and do not adversely affect the antimicrobial action thereof. When nonanoic acid is used as antimicrobial agent according to the invention, as a rule no further antimicrobial agent will be required and according to one embodiment of the invention the food essentially contains exclusively nonanoic acid as antimicrobial agent, that is to say in the amounts specified above (in per cent by mass or ppm).
However, it can not be entirely precluded that in addition to the nonanoic acid minor amounts of one or more further antimicrobial agents known per se are present, such as the agents which are mentioned below. Therefore, "essentially exclusively" is defined as meaning that the nonanoic acid makes up at least 80 % (m m), preferably at least 90 % (m/m) and more preferentially at least 95 - 99 % (m/m) of all antimicrobial constituents present (that is to say added to the food in order to achieve an antimicrobial action).
Furthermore it is possible to use nonanoic acid in a mixture with one or more antimicrobial agents which are known per se and are compatible with nonanoic acid, a synergistic effect possibly being able to be obtained. In this case - compared with the use of the known agent as such - the nonanoic acid will as a rule replace some of the quantity of the known antimicrobial agent usually used.
Nonanoic acid will as a rule make up at least 30 % (m/m), preferably at least 50 % (m/m) and more preferentially at least 70 % (m m) of the total antimicrobial constituents in such mixtures.
A few non-limiting examples of antimicrobial agents that can be used according to the invention in combination with nonanoic acid are: sorbic acid and salts thereof, benzoic acid and salts thereof, para-hydroxybenzoic acid or esters thereof, propionic acid and salts thereof, pimaricin, polyethylene glycol, ethylene/propylene oxides, sodium diacetate, caprylic acid (octanoic acid), ethyl formate, tylosin, polyphosphate, metabisulphite, nisin, subtilin and diethyl pyrocarbonate.
The nonanoic acid can furthermore be used in combination with agents for adjusting the acidity, including the acids acceptable for foods, such as citric acid, acetic acid and the like. In this context the nonanoic acid can, in particular, protect the food (which in this case can have a pH in the range from 2 to 6) against acid-resistant moulds. Examples of such acid-resistant moulds are, but are not restricted to, Penicillium roqueforti, P. carneum, P. italicum, Monascus ruber and/or Paecilomyces variotii (which occur, for example, in rye bread); and Penicillium glandicola, Penicillium roqueforti, Aspergillus flavus, Aspergillus candidus and or Aspergillus terreus (which, for example, occur in products which have been preserved by acid, such as sour and/or sweet-sour preserves). More generally, according to the invention it is preferable that at least some, and preferably an appreciable proportion, of the nonanoic acid is present in the undissociated form in the food.
The general rule in this context is that the amount of undissociated nonanoic acid increases at lower pH: for instance, approximately 90 % of the nonanoic acid is present in undissociated form at a pH of approximately 3.8.
According to one aspect of the invention, nonanoic acid is therefore also used in foods which have a low pH, such as a pH in the range 2 to 6, preferably 3 to 5.8, or 4 to 5.6.
For instance, for example, the pH of cheese rind is around 4.8 - 5.3.
In addition to the antimicrobial, in particular antifungal, action described above, the use of nonanoic acid according to the invention can also yield the following further advantages: nonanoic acid is a stable molecule in both the dissociated and undissociated form.
The long alkyl chain is inert and renders the molecule barely reactive. nonanoic acid is a natural substance which occurs in plants, inter alia; - nonanoic acid has been approved for use in foods (inter alia by the FDA); nonanoic acid remains stable under the majority of processing steps/processes for food products; nonanoic acid is less susceptible to UV light than is, for example, natamycin; nonanoic acid is stable in the presence of metals in metallic form; - nonanoic acid is stable under heating.
The invention has been described above with reference to a preferred embodiment thereof; that is to say use in foods, in particular in dairy products.
However, it will be clear to those skilled in the art from the above description that nonanoic acid can also find use outside the food sector as an antifungal, yeast-inhibiting and/or antibacterial agent. In this context it will, in particular, be an advantage that nonanoic acid has been approved for use in foods, so that it can be used in applications where it can come into contact with foods or the human body, such as with the skin.
A number of possible, non-limiting applications are: use as or in disinfectant(s), cleaning agent(s) and the like, for both domestic and industrial applications; disinfection and/or cleaning (including preventive treatment) of conveyor belts, pallets and the like; disinfection and/or cleaning (including preventive treatment) of apparatus, products and/or surfaces which come into contact with foods, such as cutting machines, mixers, stirrers, sorting equipment, filling machines and other equipment from the food processing industry; vats, dishes, tanks, plates, containers and other holders; and also worktops, sink units and the like; both domestic and industrial; disinfection and/or cleaning (including preventive treatment) of areas which may or may not be enclosed, in particular areas in which food products are processed and/or stored, such as cupboards, refrigerators, kitchens, factory areas, freight areas, warehouses and the like (both domestic and industrial); and in particular cheese warehouses and other commercial premises where P. discolor can occur; coating and/or (preventive) treatment of packaging for, for example, foods (such as fruit, vegetables, cheese and the like), for example made of materials such as plastic, paper, cardboard or shaped cardboard; protection of fruit, such as oranges, lemons, grapefruit, apples, pears; nuts and
(dried) southern fruits, coffee, tea, tobacco and the like, and also of cut flowers and bulbs, against moulds and/or bacteria, before or during transport and/or during (long- term) storage, for example in a warehouse or in an (optionally) air-conditioned fruit store; disinfection and/or cleaning (including preventive treatment) of, for example, tents or tarpaulins, and also indoors (for example on walls) to prevent or to counteract mould growth, for example as a consequence of damp; protection and/or treatment of wood and similar materials; use in cosmetics and skincare products; use for pharmaceutical applications, for example to prevent and treat fungal infections and yeast infections, such as Candida. These aspects of the invention in general comprise the treatment of a surface or substrate that is susceptible to mould formation, or that can be contaminated or infected by a mould and/or the spores thereof, with an amount of nonanoic acid which has an effective antifungal and/or antibacterial action.
This amount will differ depending on the application and the way in which the nonanoic acid is used on the surface or substrate.
As a rule the presence of nonanoic acid in amounts of 10 - 10,000 ppm, in particular 100 - 2,000 ppm, will again be sufficient to achieve an antimicrobial, in particular antifungal, action, although higher concentrations can be used for some applications. The nonanoic acid can be used on the surface or substrate in any suitable way, such as, once again, spraying or brushing with nonanoic acid (for example in the form of an aqueous solution), by applying a nonanoic acid-containing coating or by use of an atomised spray containing nonanoic acid.
This treatment can optionally be repeated.
In this context the nonanoic acid can once again be used instead of, or together with, disinfectants which may be known for the envisaged application, as well as in combination with other agents or constituents customary for the envisaged application. For these applications, the nonanoic acid and any other constituents can optionally be marketed in a suitable container, for example in a bottle or in the form of a spray.
A particular application of nonanoic acid according to the invention furthermore relates to the control - in particular the inhibition - of bacterial growth during fermentation processes, such as the preparation of fermented food products such as yoghurt. For this application use is made in particular of the antibacterial action of nonanoic acid. For instance, nonanoic acid can be used to control the pH during or after such fermentation processes and in particular to prevent and/or reduce post-acidification of, for example, yoghurt, as explained in more detail in the examples.
The taste of the yoghurt is retained for longer as a result.
In addition, the antimicrobial, in particular antifungal, action according to the invention will also be obtained.
The invention will now be explained with reference to the following non-limiting examples and the figures, in which:
Figure 1 is a graph (time against visible intensity of mould formation) in which the effect of nonanoic acid on mould formation on Gouda cheese is shown; Figure 2 is a graph (time against number of bacteria) which shows the effect of nonanoic acid (pelargonic acid) on the development of yoghurt bacteria at 7 °C; -
Figure 3 is a graph (time against pH) which shows the effect of nonanoic acid (pelargonic acid) on the post-acidification of yoghurt at 7 °C; Figure 4 is a graph (time against number of bacteria) which shows the effect of nonanoic acid (pelargonic acid) on the development of yoghurt bacteria at 32 °C; Figure 5 is a graph (time against pH) which shows the effect of nonanoic acid (pelargonic acid) on the post-acidification of yoghurt at 32 °C;
Figure 6 is a plot (time against number of bacteria) that shows the influence of nonanoic acid (pelargonic acid) on the development of surface flora on cheese rind; Figure 7 is a plot (time against number) that shows the effect of nonanoic acid (pelargonic acid) on the development of D. hansenii, S. cereviseae, C. lipolytica and R. rubra;
Figures 8 A and 8B are photographs which show the effect of natamycin (Figure 8 A) and nonanoic acid (Figure 8B), respectively, on the inhibition of the growth of P. discolor on blocks of cheese rind;
Figure 9 is a graph (time against number of bacteria) which shows the effect of nonanoic acid on the growth of Bacillus cereus in soup;
Figure 10 is a graph (time against number of bacteria) which shows the effect of nonanoic acid on the growth of Staphylococcus aureus in soup;
Figure 11 is a graph (time against number of cells) which shows the effect of nonanoic acid on the growth of Debaromyces hansenii in a milk/fruit juice drink; Figure 2 is a graph (time against number of cells) which shows the effect of nonanoic acid on the growth of Penicillium italicum in a milk/fruit juice drink.
Experimental
Example 1 : Use of nonanoic acid in Gouda cheese
A trial production of Gouda cheeses was made. In this batch of cheeses one series was treated with 1000 ppm nonanoic acid (nonanoic acid) and the other series was not treated with a fungicide (blank). The two series were inoculated with spores of the mould P. discolor (0.1 spore/cm2) and stored at 13 °C and 88 % relative humidity. All individual cheeses were assessed visually at frequent intervals for the extent of the presence of mould. The following scale was used for the optical assessment of the intensity of visible moulds;
0 = no mould 1 = some mould
2 = distinct mould
3 = considerable mould
4 = very considerable mould or overgrown with mould.
The results are shown diagrammatically in Figure 1. In the case of the cheeses without fungicide slight mould growth (intensity 1) was detectable after about 60 days.
In the case of the series of cheeses treated with nonanoic acid it was 66 days before mould growth (intensity 1) was observed.
Example 2: Use of nonanoic acid in yoghurt to prevent post-acidification In an experiment various concentrations of nonanoic acid were added to freshly prepared yoghurt.
One series was monitored for 8 hours at the culture temperature (filling, 32 °C) and another series was incubated for 14 days at 7 °C (refrigerator temperature).
This was carried out to investigate the extent to which nonanoic acid has an effect during yoghurt fermentation and/or during storage of the filled packs of yoghurt.
For both series the pH was determined and the number of yoghurt bacteria.
The results are shown in Figures 2 - 5. Addition of 1,000 ppm nonanoic acid substantially prevented post-acidification (32 °C) and the number of yoghurt bacteria was reduced by 2 log units. At 7 °C an effect on the post-acidification was already detectable at lower nonanoic acid contents (200 ppm). Addition of 1,000 ppm prevented post- acidification Virtually completely when storing at refrigerator temperature and the number of yoghurt bacteria decreased by 4 log units.
Example 3: Effect of nonanoic acid on the surface flora of cheese rind
The effect of nonanoic acid on the surface flora on cheese rind was determined.
The results (time against number of bacteria) are shown in Figure 6.
The effect of nonanoic acid (pelargonic acid) on the development of D. hansenii, S. cereviseae, C. lipolytica and R. rubra was also determined.
The results (time against number) are shown in Figure 7.
Example 4: Use on blocks of cheese rind
In this experiment blocks of cheese rind were inoculated with P. discolor. The blocks were incubated at 20 °C and high relative humidity (95 %). These conditions were employed to provide the mould with the optimum opportunity to grow and are therefore more severe than the usual conditions for maturing cheese.
The results are given in Figure 8, which shows photographs of the blocks of cheese rind taken two weeks after inoculating with P. discolor.
One series was treated with natamycin (Figure 8A) and the other series with nonanoic acid (Figure 8B).
It can clearly be seen that after 2 weeks mould formation was inhibited in the blocks treated with nonanoic acid.
Example 5: Use in soup
In this experiment a creamy mushroom soup with parsley (chill-fresh product obtained from the Albert Heijn delicatessen in March 2000) was inoculated with
104 CFU/ml (colony-forming units per ml soup) of Bacillus cereus (NIZO B443) or with 104 CFU/ml Staphylococcus aureus (NIZO B1211).
The soup was then incubated at 20 °C, without and with increasing concentrations of nonanoic acid (100, 500 and 1,000 ppm).
Samples were taken at the times indicated in Figures 9 and 10 (Figure 9 for B. cereus and Figure 10 for S. aureus).
From each sample a series of dilutions was plated to determine the number of CFU/ml soup.
The B. cereus samples were plated on mannitol egg yolk polymyxin agar (MYP) and incubated for 24 hours at 30 °C; the S. aureus samples were plated on Baird-Parker egg yolk tellurite agar (BP) and incubated for 48 hours at 37 °C. The results are shown in Figures 9 and 10. The addition of 100 ppm nonanoic acid to the soup has a slightly inhibiting effect on the growth of both B. cereus and S. aureus, whilst with the addition of 500 or 1,000 ppm nonanoic acid the growth of both bacteria is virtually completely inhibited. Example 6: Use in a milk/fruit juice product
In this experiment a milk/fruit juice drink ("Milk & Fruit"™ from Coberco, obtained from Albert Heijn; "Milk & Fruit"™ is a chilled-fresh, pasteurised product without preservatives, consisting of 80 % drinking yoghurt and 20 % pineapple juice and has a pH value of 4.0) was inoculated with 102 CFU/ml Debaromyces hansenii (NIZO F937) or Penicillium italicum (CBS 278.58).
The milk/fruit juice drink was then incubated at 20 °C, without and with increasing concentrations of nonanoic acid (100, 500 and 1,000 ppm).
Samples were taken at the times indicated in Figures 11 and 12 (Figure 11 for D. hansenii and Figure 12 for P. italicum).
For each sample a series of dilutions was plated in order to determine the number of CFU/ml drink.
The samples were plated on oxytetracycline glucose yeast agar (OGY) and incubated for 5 days at 25 °C.
The results are shown in Figures 11 and 12. Addition of 100 ppm nonanoic acid gives complete inhibition of the growth of D. hansenii.
Addition of 100 or 500 ppm inhibits the growth of P. italicum and addition of 1,000 ppm nonanoic acid gives complete inhibition of the growth of P. italicum for up to 6 days.
GENERAL DESCRIPTION OF CARBOXYLIC ACID
Carboxylic acid is an organic compound whose molecules contain carboxyl group and have the condensed chemical formula R-C(=O)-OH in which a carbon atom is bonded to an oxygen atom by a solid bond and to a hydroxyl group by a single bond), where R is a hydrogen atom, an alkyl group, or an aryl group. Carboxylic acids can be synthesized if aldehyde is oxidized. Aldehyde can be obtained by oxidation of primary alcohol. Accordingly, carboxylic acid can be obtained by complete oxidation of primary alcohol. A variety of Carboxylic acids are abundant in nature and many carboxylic acids have their own trivial names. Examples are shown in table. In substitutive nomenclature, their names are formed by adding -oic acid' as the suffix to the name of the parent compound. The first character of carboxylic acid is acidity due to dissociation into H+ cations and RCOO- anions in aqueous solution. The two oxygen atoms are electronegatively charged and the hydrogen of a carboxyl group can be easily removed. The presence of electronegative groups next to the carboxylic group increases the acidity. For example, trichloroacetic acid is a stronger acid than acetic acid. Carboxylic acid is useful as a parent material to prepare many chemical derivatives due to the weak acidity of the hydroxyl hydrogen or due to the difference in electronegativity between carbon and oxygen. The easy dissociation of the hydroxyl oxygen-hydrogen provide reactions to form an ester with an alcohol and to form a water-soluble salt with an alkali. Almost infinite esters are formed through condensation reaction called esterification between carboxylic acid and alcohol, which produces water. The second reaction theory is the addition of electrons to the electron-deficient carbon atom of the carboxyl group. One more theory is decarboxylation (removal of carbon dioxide form carboxyl group). Carboxylic acids are used to synthesize acyl halides and acid anhydrides which are generally not target compounds. They are used as intermediates for the synthesis esters and amides, important derivatives from carboxylic acid in biochemistry as well as in industrial fields. There are almost infinite esters obtained from carboxylic acids. Esters are formed by removal of water from an acid and an alcohol. Carboxylic acid esters are used as in a variety of direct and indirect applications. Lower chain esters are used as flavouring base materials, plasticizers, solvent carriers and coupling agents. Higher chain compounds are used as components in metalworking fluids, surfactants, lubricants, detergents, oiling agents, emulsifiers, wetting agents textile treatments and emollients, They are also used as intermediates for the manufacture of a variety of target compounds. The almost infinite esters provide a wide range of viscosity, specific gravity, vapor pressure, boiling point, and other physical and chemical properties for the proper application selections. Amides are formed from the reaction of a carboxylic acids with an amine. Carboxylic acid's reaction to link amino acids is wide in nature to form proteins (amide), the principal constituents of the protoplasm of all cells. Polyamide is a polymer containing repeated amide groups such as various kinds of nylon and polyacrylamides. Carboxylic acid are in our lives.
ALIPHATIC CARBOXYLIC ACIDS
COMMON NAME
SYSTEMATIC NAME
CAS RN
FORMULA
MELTING POINT
Formic Acid Methanoic acid 64-18-6 HCOOH
8.5 C
Acetic Acid Ethanoic acid 64-19-7 CH3COOH
16.5 C
Carboxyethane Propionic Acid 79-09-4 CH3CH2COOH
-21.5 C
Butyric Acid n-Butanoic acid 107-92-6 CH3(CH2)2COOH
-8 C
Valeric Acid n-Pentanoic Acid 109-52-4 CH3(CH2)3COOH
-19 C
Caproic Acid n-Hexanoic Acid 142-62-1 CH3(CH2)4COOH
-3 C
Enanthoic Acid n-Heptanoic acid 111-14-8 CH3(CH2)5COOH
-10.5 C
Caprylic Acid n-Octanoic Acid 124-07-2 CH3(CH2)6COOH
16 C
alpha-Ethylcaproic Acid 2-Ethylhexanoic Acid 149-57-5 CH3(CH2)3CH(C2H5)COOH
-59 C
Valproic Acid 2-Propylpentanoic Acid 99-66-1 (CH3CH2CH2)2CHCOOH
120 C
Pelargonic Acid n-Nonanoic Acid 112-05-0 CH3(CH2)7COOH
48 C
Capric Acid n-Decanoic Acid 334-48-5 CH3(CH2)8COOH
31 C
Nonanoic acid is a fatty acid which occurs naturally as esters are the oil of pelargonium. Synthetic esters, such as methyl nonanoate, are used as flavorings. Pelargonic acid is an organic compound composed of a nine-carbon chain terminating in a carboxylic acid. It is an oily liquid with an unpleasant, rancid odor. It is nearly insoluble in water, but well soluble in chloroform and ether.
Nonanoic acid, also called pelargonic acid, is an organic compound with structural formula CH3(CH2)7CO2H. It is a nine-carbon fatty acid. Nonanoic acid is a colorless oily liquid with an unpleasant, rancid odor. It is nearly insoluble in water, but very soluble in organic solvents. The esters and salts of nonanoic acid are called nonanoates. Its refractive index is 1.4322. Its critical point is at 712 K (439 °C) and 2.35 MPa.