真空包装鸡肉早餐肠中细菌总数生长预测模型的拟合优度比较

Goodness-of-Fit Comparison of Growth Models for the Total Bacterial Count in Vacuum-Packaged Chicken Breakfast Sausage

为比较不同生长预测模型对真空包装鸡肉早餐肠中细菌总数生长情况的拟合效果,观察在不同贮藏温度(2~15℃)下,使用Baranyi、修正的Gompertz及修正的Logistic模型分别描述细菌总数随时间变化的情况,以及使用Arrhenius方程与平方根模型描述一级模型所得参数随温度变化的情况。通过计算各模型的评价参数(均方误差平方根RMSE、回归系数R2、赤池信息准则与贝叶斯信息准则),参考模型所得特征值及货架期残差值,评价各模型的拟合优度,寻找最优组合。结果表明:Baranyi模型所得方程的评价参数最优,最大比生长速率(μmax)最大,所得产品货架期残差值较小;应用修正的Gompertz模型更有利于优化二级模型评价参数;而修正的Logistic模型拟合所得初始菌数N0值偏小,且将15℃贮藏组延滞时间λ计算为负值。因此Baranyi模型的拟合优度最高,其次为修正的Gompertz模型,最后为修正的Logistic模型。应用Arrhenius方程与平方根模型均能够成功拟合,但未能得出拟合更优者。

In order to compare the goodness-of-fit of growth models for the total bacterial count in vacuum-packaged chicken breakfast sausage, the primary models Baranyi, modified Gompertz and modified Logistic, and the secondary models Arrhenius and square root equations were chosen for conducting following studies, respectively. They were compared by calculating their indices(such as root mean square error(RMSE), R2, Akaike information criterion and Bayesian information criterion), and the characteristic values and residuals of the shelf life model. Results showed that the Baranyi model exhibited the best performance indices and the highest maximum specific growth rate(μmax) and provided smaller shelf life residuals, while the modified Gompertz model was better in optimizing the secondary model and the modified Logistic model presented the wrong characteristic values. Thus the goodness-of-fit of the Baranyi model was the best, followed by the modified Gompertz model, and the modified Logistic model showed the worst goodness-of-fit. The comparison of Arrhenius equation and square root equation did not draw a conclusion.