蜡样芽胞杆菌生长/非生长界面模型的建立和评价

蜡样芽胞杆菌是软烤虾仁产品的主要变质菌,它是一种条件致病菌,通过产生腹泻毒素和呕吐毒素导致食物中毒。该研究旨在建立一种概率模型来预测出蜡样芽胞杆菌的生长/非生长情况或者生长概率。用lo-gistic回归模型建立不同温度、水分活度和pH环境因子作用下蜡样芽胞杆菌的生长/非生长界面模型。实验结果表明蜡样芽胞杆菌在脑心浸液肉汤培养基中生长的最低温度为9.99℃,最低水分活度为0.931,最小pH值为4.5。在此基础上建立的蜡样芽胞杆菌生长/非生长界面模型的χ2=49.73,P<0.000 1。用logistic回归模型建立的生长/非生长模型拟合效果达到极显著水平。模型的预测值同时很好地量化了环境因子对蜡样芽胞杆菌的协同作用,为软烤虾仁产品中蜡样芽胞杆菌的生长/非生长界面模型的建立提供了参考。

Modeling and evaluating the growth/no growth interface of Bacillus cereus based on temperature, water activity and pH

Bacillus cereus is a main kind of spoilage bacteria of mild-roast shrimp products,which is a kind of conditional pathogens.It can cause food poisoning mainly by producing diarrhoeal toxins and vomitive toxins.The aim of this research was to establish a probabilistic model to predict the growth/no growth conditions or growth probability of B.cereus.A logistic regression model was established to model the growth/no growth boundaries of B.cereus under the combination of different temperature,water activity and pH value.The results showed that the minimum temperature allowing the growth of B.cereus in Brain Heart Infusion was 9.9℃,the minimum water activity was 0.931,and the minimum pH was 4.5.According to it,the χ2 of the growth/no growth model for B.cereus was 49.73 and P<0.000 1.The results of goodness of fit evaluation for growth/no growth model which was based on logistic regression model were extremely significant.The predicted values also quantized the synergy of environmental factors for Bacillus cereus.This research has reference value for the establishment of growth/no growth model for Bacillus cereus in mild-roast shrimp.