巴氏杀菌乳中金黄色葡萄球菌的生长预测模型构建

巴氏杀菌乳中金黄色葡萄球菌污染可能会产生肠毒素,对人体健康造成危害。分别监测在4、10、16、20、24、28℃储藏条件下金黄色葡萄球菌在巴氏杀菌乳中的生长数据,采用Modified Gompertz模型、Logistic模型、Huang模型和Baranyi模型构建金黄色葡萄球菌动力学一级模型,采用平方根模型和Arrhenius模型建立二级模型以描述温度与相对最大生长速率(μ_max)的关系。结果显示,各温度下Modified Gompertz模型的拟合度更优,决定系数(R²)>0.98,均方根误差(RMSE)<4.6,为最合适的一级模型。二级模型中,Arrhenius模型的拟合度更优(R²=0.99,RMSE=0.60)。相较于平方根模型,外部验证显示Arrhenius模型的精确度因子(A_f)和偏差因子(B_f)分别为1.39和0.87,较接近于1,说明预测效果更好。研究结果可为巴氏杀菌乳中金黄色葡萄球菌的风险评估提供数据基础,为乳品货架安全期预测提供科学依据。

Establishment of growth model of Staphylococcus aureus in pasteurized milk

The enterotoxin of Staphylococcus aureus in pasteurized dairy would cause harm to human health. The growth kinetic of Staphylococcus aureus in pasteurized milk was monitored under 4, 10, 16, 20, 24, 28 ℃, and fitted by the Modified Gompertz model, Logistic model, Huang model and Baranyi model, respectively. The square root model and Arrhenius model were fitted to describe the maximum growth rate (μ_max) with temperature. It was shown that the Modified Gompertz model performed the best, as the determination coefficient (R²) was greater than 0.98, and root mean square error (RMSE) was smaller than 4.6. So, the Modified Gompertz model was chosen as the primary model. Compared with the square root model, the Arrhenius model was a better choice, which was indicated as R²=0.99 and RMSE=0.60. The external verification results showed that the accuracy factor (A_f) and the bias factor (B_f) of the Arrhenius model were 1.39 and 0.87, respectively, which well indicated its prediction potential. The results of this study offered references to predict the shelf-life of dairy products, and provided parts of the input data for microbial risk assessment of Staphylococcus aureus in pasteurized milk.