Studies On Improving Microbial Food Safety Of Fresh-Cut Green Peppers

Fresh-cut vegetables and fruits with freshness, nutrition, convenience and high edibilityrate are popular in developed countries and they are also becoming fashionable in China. Inorder to ensure the safety of the fresh-cut vegetables, they are must be as safe as uncookedaccording to countries regulation. It’s still a hot point for researchers to find out how toeliminate the food-borne pathogen on fresh-cut vegetables and reduce their threat to the healthof consumers. The main objective of this study was to evaluate the effectiveness of sanitizersin water: NaClO、 citric acid、 ClO2、 peroxyacetic acid and acidified sodium chlorite forreducing populations of Salmonella typhimurium, Listeria monocytogenes, E. coli O157:H7from inoculated fresh-cut of green peppers under laboratory. Evaluate pathogen inactivationon inoculated fresh-cut of green peppers for optimization of electron beam treatmentsimulated commercial processing conditions. And combined citric acid and acidified sodiumchlorite with a1R electron beam irradiation. The aim of this study was to provide thefundamental theories for the application on microbiolgical sanitary quality of fresh-cutproducts. The main conclusions were as follows:1. Efficacies of several chemical sanitizers on the reduction of Salmonella typhimurium,Listeria monocytogenes and E. coli O157:H7on fresh-cut green bell peppers shows different.The treatment with ASC (1000mg/L, pH=2.5) is the best sanitizer for fresh-cut peppers. Thetreatment of ASC caused a significant reduction of Salmonella typhimurium by2.22lg CFU/g,E. coli O157:H7by3.15lg CFU/g and Listeria monocytogenes by1.68lg CFU/g,respectively on day0.2. During the storage of the populations of Salmonella typhimurium and E. coli O157:H7on fresh-cut of green peppers decreased gradually while that of Listeria monocytogenesincreased, and the soluble solid content were decline after rising, vitamin C were decreasedgradually, cell membrane permeability increase gradually. The teatment of ASC can not onlyimprove its’ microorganism safety, but also enhance the quality of them and extend the shelflife.3. Salmonella typhimurium and E. coli O157:H7bacterials were eliminated by electronbeam irradiation efficaciously. The D10values of them are0.42R、0.30R and0.31Rrespectively. On day0, peppers teated with1R had declined Salmonella typhimurium, Listeria monocytogenes and E. coli O157:H7bacterial counts of2.99lg CFU/g、4.42lgCFU/g and3.82lg CFU/g, respectively. Suitable doses (≤1.5R) of the electron beam did notaffect objective color and descriptive attribute falvor and delaying the products softing duringthe storage at4℃.4.On day0, peppers washed with acidified sodium chlorite (1000mg/L, pH=2.5) andcitric acid (10g/L), prior to irradiate at1R doses treatment improve the disinfection of theelectron beam, with significantly reduced the population of Salmonella typhimurium, Listeriamonocytogenes and E. coli O157:H7bacterial counts of3.23lg CFU/g and3.08lg CFU/g,5.09lg CFU/g and4.79lg CFU/g,4.27lg CFU/g and4.14lg CFU/g respectively on fresh-cutof green peppers.