零售鸡肉中沙门氏菌生长预测模型的建立

Establishment of Growth Prediction Model for Salmonella in Retail Chicken

为了建立零售鸡肉中沙门氏菌的生长预测模型,以在超市购买的新鲜鸡肉和肠炎沙门氏菌作为研究对象,选择4、10、16、25、30、37℃条件,对肠炎沙门氏菌在零售鸡肉中的生长情况进行研究,绘制生长曲线。对一级模型,用Curve Expert软件中的Gompertz、Richards、Logistic 3种模型和DMFit软件中的Baranyi模型进行拟合,以确定最适用模型。4种模型拟合后的Baranyi模型相关系数都在0.98以上。数据表明该模型拟合程度最好,最适合预测沙门氏菌在鸡肉中的生长动态。二级模型是将一级模型拟合的数据带入Ratkowsky方程。此方程描述的是温度对最大生长速率的影响。通过准确因子、偏差因子以及均方根误差,对模型的准确性进行检验。结果显示模型的准确因子为1.129 698,偏差因子为0.984 85,均方根误差为0.091 5,决定系数R2为0.982 5,说明建立的模型可靠性高。

To establish the growth prediction model for Salmonella in retail chicken,Salmonella enteritis in fresh chicken sampled from supermarket at different temperature were studied. The growth of Salmonella enteritidis in retail chicken was studied at 4,10,16,25,30 and 37 ℃,and the growth curve was drawn. The first grade model was fitted with 3 models,including Gompertz,Richards and Logistic in Curve Expert software and Baranyi model in DMFit software,and the most suitable model was determined. After fitted by four models,Baranyi model showed the best fitting with all the correlation coefficients at different temperature above 0.98,which was the most suitable for predicting the growth dynamics of Salmonella in chicken. The second level model,which described the effect of temperature on the maximum growth rate,was predicted by putting the fitting data obtained from the first level into Ratkowsky equation. The accuracy of the model was tested by the accuracy factor,the bias factor and the root mean square error. Results showed that the accuracy factor of this second growth model was 1.129 698,the bias factor was 0.984 85. the root mean square error was 0.091 5,and the coefficient of determination was 0.982 5. The results showed that the reliability of the established model was high.