Study On The Survey And Risk Assessment Of Salmonella In Cooked Marinated Chicken

Cooked marinated chicken is one of traditional famous braised pork products,it is the Chinese food culture nurtured on behalf of food.Roast chicken has a rich flavor lasting,bright color,meat melted by domestic and are popular with consumers.Salmonella is the most common foodborne pathogens in chicken,because of the traditional chicken processing,distribution and sales environment,cooking,eating and other factors,cooked marinated chicken is very easy for people to be infected salmonella usually,It has potential foodborne risks for the health of consumers.The study conducted mainly the pollution of Salmonella of chilled chicken in different cities in Henan and roast chicken in Zhengzhou.The study selected fresh chicken produced by a factory in Henan and SPA that was isolated from sales-chicken as experimental materials,growth characteristics of SPA under different conditions of fluctuating temperatures and different p H conditions.This research conducted a survey of consumption about chicken products in five different regions’ residents to people in Zhengzhou,conducted a survey of consumption of chicken products to obtain dietary consumption of Zhengzhou residents,the storage temperature and time in circulation and consumption aspects,epidemiological data and population data of salmonella,used @Risk5.5-software to conduct Monte Carlo simulation to construct risk assessment model for Salmonella from sales to consumption stage to estimate the probability of risk.In this study,the establishment of chicken risk assessment model of Salmonella in roast chicken provided a scientific basis for improving the food safety of chicken products and foodborne pathogens risk management.The results showed that:(1)The positive rate of 200 parts of chilled chicken breasts and legs from 20 supermarkets and 20 farmers’ markets in Henan was 10.50%(21/200)and 108 parts of roast chicken products from five districts in Zhengzhou was 8.33%(9/108).Concentration range of pollution in roast chicken was that: The initial Salmonella contamination levels was 1.865 ± 0.6513 Log CFU / g in cooked marinated chicken.(2)By comparing the effects under different sets of dynamic fluctuating temperatures(including 4℃,6℃,8℃,10℃,12℃,15℃,20℃,25℃,30℃,35℃)with constant temperature 15℃,20℃ to the growth characteristics of SPA showed that at t 25℃,under conditions of fluctuating temperatures,4℃,6℃,8℃,10 ℃,15 ℃,20 ℃,at a temperature of 25 ℃,when SPA was at the lag time the growth rate and the temperatures exhibited polynomial function;Under fluctuating temperature conditions,when the temperature dropped to a lower temperature,he number of colonies of SPA will significantly decreased,when the temperature dropped to a lower temperature at higher temperatures SPA from the number of colonies will be significantly decreased,conducting analysis of variance to different temperature,the result showed that the rate of decrease existed significant difference when a temperature difference was 31℃,26℃,25℃ and 13℃,14℃,16℃ and 12℃ and 4℃,8℃;4℃,when the temperature difference was between 8 ℃,13 ℃,14 ℃,there were no significant difference.At 15℃,conducting independent sample T-test to average rate,the result showed that for the same number of colonies at constant temperature groups and sets of fluctuating temperature conditions range average rate independent sample T-test,in addition to the number of colonies in the range of 8 ~ 9Log CFU / g,the significance test values were less than 0.05 with a significant difference.At 20℃,in addition to the number of colonies in the range of 4 ~ 5 and 6~7 Log CFU / g range,thermostatic group with automatic temperature test group was significantly greater than 0.05,the difference was not significant,other colonies,the significant difference test group were less than 0.05 with a significant difference.(3)By curve fitting simulation to the five Growth curves at different fluctuation temperatures and constant temperatures 15℃,20℃ in cooked marinated chicken to establish growth kinetics model and Monte Carlo simulation to validate the model.Statistical indicators MSE and RMSE values were lower,the first three sets 1,2,3 growth curves were used for curve fitting and got a standard deviation of 0.30 Log CFU/g.The standard deviation of prediction of other sets of 4,5 groups and 15℃,20℃ was 0.53 Log CFU/g.Meanwhile,by using dynamic model to the two sets of dynamic fluctuation temperatures and two constant temperature,the prediction residuals have 70.4% in-0.5 Log CFU/g and 0.5 Log CFU/g range,thus the prediction accuracy of the model is good.(4)By using the software @ Risk5.5 to simulate the chicken meat contamination,consumer consumption,frequency of consumption,edible way,storage time and temperature from the store to family and combining epidemiological data and survey data to set up risk assessment model from sales outlets to consumer consumption,the risk assessment model estimated the probability of residents per person each year in Zhengzhou due to consumption of chicken meat per person is sick of 9.476 × 10-6(9476/1000000000).