Decontamination of fresh parsley leaves by sequential wash treatment in chlorine and lactic acid solutions

Abstract

Due to concerns about the formation of carcinogenic disinfection by-products (DBPs) during decontamination process of fresh produce by chlorine based sanitisers, there has been interest in finding alternative sanitizers. Despite the intensive research, there is still no widely accepted cost effective sanitizer and most of the sanitizers in the marketplace has limited decontamination efficiency. By using parsley leaves as test vegetable, this study aimed to investigate the possibility of using a two stage sequential wash to increase the disinfection efficiency, while reducing the concentration of chlorine by application of a second stage wash with lactic acid (LA) solution. Washing of parsley leaves in 100 ±10 ppm chlorine solution for 3 min resulted in an average of 1.01±0.64 log reduction, whereas a 1 min wash in 1.0% (w/w) LA returned an average of 1.25±0.39 log reduction for TAC. Increasing washing time in chlorine or LA solutions alone did not increase the decontamination efficiency, significantly. However, 3 min wash in 100 ±10 ppm chlorine, followed by a 1 min wash 1.0% (w/w) LA (sequential wash) increased the decontamination efficiency significantly returning an average of 2.45±0.52 log reduction in total viable count. Sequential wash was also effective in reduction of artificially inoculated non-pathogenic strains of Escherichia coli, Salmonella and Listeria spp. Concentration of DBPs determined by GC-MS in wash water samples were below the limits set by United States Environmental Protection Agency.

Keywords

• Decontamination
• disinfection
• parsley
• chlorine
• lactic acid
• sequential wash
• disinfection by-products

Taze maydanoz yapraklarının klor ve laktik asit solüsyonlarında ardışık yıkama işlemiyle dekontaminasyonu

Abstract

Klor bazlı dezenfektanlar ile taze ürünlerin dekontaminasyon süreci sırasında kanserojen dezenfeksiyon yan ürünlerinin (DBPs) oluşumu konusundaki endişeler nedeniyle alternatif dezenfektanlar bulma konusunda ilgi artmaktadır. Yoğun araştırmalara rağmen, hala yaygın olarak kabul görmüş uygun maliyetli bir dezenfektan bulunmamaktadır ve piyasadaki dezenfektanların çoğu sınırlı dekontaminasyon verimliliğine sahiptir. u çalışmada, maydanoz yaprakları test sebzesi olarak kullanılarak, dezenfeksiyon verimliliğini artırmak amacıyla iki aşamalı ardışık yıkamanın uygulanabilirliği araştırılmış ve laktik asit (LA) solüsyonu ile yapılan ikinci aşama yıkama ile klor konsantrasyonunun azaltılması hedeflenmiştir. Maydanoz yapraklarının 100 ± 10 ppm klor solüsyonunda 3 dakika yıkanması toplam canlı sayısında ortalama 1,01 ± 0,64 log azalmaya yol açarken, %1,0 (a/a) LA’da 1 dakikalık yıkama ortalama 1,25 ± 0,39 log azalmaya yol açmıştır. Sadece klor veya LA solüsyonlarında yıkama süresini artırmak, dekontaminasyon verimliliğini önemli ölçüde artırmamıştır. Bununla birlikte, 100 ± 10 ppm klorda 3 dakikalık yıkama, ardından %1,0 (a/a) LA’da 1 dakikalık yıkama (sıralı yıkama), dekontaminasyon verimliliğini önemli ölçüde artırarak toplam canlı sayısında ortalama 2,45 ± 0,52 log azalma sağlamıştır. Sıralı yıkamanın, yapay olarak aşılanmış patojenik olmayan Escherichia coli, Salmonella ve Listeria türlerinin azaltılmasında da etkili olduğu bulunmuştur. Yıkama suyu örneklerinde GC-MS ile belirlenen DBPs konsantrasyonlarının Amerika Birleşik Devletleri Çevre Koruma Ajansı tarafından belirlenen limitlerin altında olduğu tespit edilmiştir.

Keywords

• Dekontaminasyon
• dezenfeksiyon
• maydanoz
• klor
• laktik asit
• sıralı yıkama
• dezenfeksiyon yan ürünleri

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