关键词: 沙门氏菌, 生鲜猪肉, 即食食物, 交叉污染, 定量风险评估

Abstract: In this study, the cross-contamination of Salmonella from raw pork to ready-to-eat (RTE) foods in the domestic kitchen was evaluated by using a quantitative risk assessment model, and the key factors involved were examined. Risk management strategies were put forward. Relevant data were collected from published literature to analyze the possibility and level of Salmonella contamination in fresh pork. Based on these data combined with resident consumption habit survey data from the statistical yearbook of China, a predictive model was developed for describing the growth of Salmonella in fresh pork at room temperature. The model was run through Monte Carlo simulations using the @Risk software. In order to quantitatively estimate the risk of Salmonella positioning in Chinese consumers caused by cross-contamination from fresh pork to RTE foods in the kitchen, hazard recognition, exposure estimation, description of hazard characteristics and risk analysis were carried out. According to the data we collected, the highest probability of Salmonella prevalence in fresh pork from the market was 15.5%. After being stored at room temperature initially and then refrigerated temperature for several hours, the number of Salmonella in fresh pork was ?1.95 (lg(CFU/g)) with a 90% confidence interval of ?5.32 to 0.67 (lg(CFU/g)). Cross-contamination from fresh pork to RTE foods occurred through contact with the cutting boards, hands and knives. The daily per capita intake of Salmonella in the consumers was ?4.77 (lg(CFU/g)) with a 90% confidence interval of ?8.73 to ?1.24 (lg(CFU/g)) as calculated from the predictive models for Salmonella growth and cross-contamination. The results of quantitative risk assessment showed that the probability of Salmonella poisoning due to Salmonella contamination of fresh pork in the kitchen was 4.15 × 10-6. The annual number of infections predicted from the dose-response relationship of Salmonella was consistent with the observed number of salmonellosis cases (about 95 299). The initial contamination level of Salmonella in fresh pork was the primary cause of cross-contamination of RTE foods; meanwhile, contact of raw and cooked foods with the same chopping boards was another important factor. The risk of cross-contamination could be reduced by controlling refrigerator temperature and storage time. It is concluded that the probability of Salmonella poisoning from fresh pork in our domestic kitchen depends on the initial level of Salmonella in fresh pork and consumers’ habit of separate usage of chopping boards and choppers for raw and cooked foods as well as refrigerator usage habit. All these factors are closely related to the seasons, the standard of living and the level of socio-economic development.

Key words: Salmonella, fresh pork, ready-to-eat food, cross-contamination, quantitative risk assessment