Development of Natural vegetable sanitizer from Thai local herbs

Abstract

Nowadays, food safety becomes public concern, especially in fresh produce; fresh vegetables and fruits. The CDC has been reported at least 7 outbreaks from fresh produce in the past 3 years; for example, Escherichia coli O121 in raw clover sprouts (2014), E. coli O157:H7 in ready-to-eat salads (2013), Salmonella Saintpaul in cucumbers (2013), Salmonella Typhimurium and Newport in cantaloupe (2012), and E. coli O157:H7 in spinach and spring mix salad (2012). Washing, before consuming, is the most important step in order to prevent foodborne outbreak in fresh produces. Therefore, this research was aimed to develop vegetable sanitizer from crude extracts of Acacia concinna (Willd.) D.C (Som-poi), Capsicum annuum (Chili), Cymbopogon citratus (Lemongrass), Citrus hystrix (Kaffir lime) and Chrysanthemum indicum L. (Chrysanthemum) in order to reduce foodborne bacteria in fresh vegetable. These herbs have been reported for their antibacterial activity (Pitinidhipat and Yasurin, 2012; Utami et al., 2012; Saenghiruna and Yasurin, Lazuardi et al., 2013; 2013; Piya-isarakul and Yasurin, 2013; Saenghiruna et al., 2014; Dung et al., 2014). The 18 treatments with 3 different crude extracts percentage (0.5, 1 and 1.5%), 3 different volumes (3, 5, and 10 ml.) and 2 different soaking times (10 and 20 min) were investigated for their antibacterial synergistic activity using Lactuca sataiva (Lettuce) as vegetable model. The MPN, total place count on PCA, BHI agar for Listeria monocytogenes count, and SS agar for Salmonella sp. count were used to evaluate the antibacterial efficiency of vegetable sanitizer. The results showed that treatment 18 (using 10 ml of 1.5% crude extracts with 20 min soaking time) gave the highest bacterial efficiency statistically by vegetable sanitizer comparing with the commercial brand. The MPN number, the total plate count, and the L. monocytogenes count were 1.34 ±0.19 MPN/ml, 1.62 ± 1.02 log CFU/ml, and 1.31 ± 0.40 log CFU/ml, respectively. The Salmonella sp. was not found. The t-test has been done by using SAS on log CFU/ml with P0.05. It was found that crude extract percentage, used volume, and soaking time affected the antibacterial efficiency of this vegetable sanitizer.