不同贮藏温度下进口生鲜牛肉中大肠杆菌生长预测模型的建立

Establishment of Growth Prediction Model of Escherichia coli in Imported Fresh Beef at Different Temperatures

为了建立不同温度条件下进口生鲜牛肉中大肠杆菌O157:H7的生长预测模型。将于超市购买的进口生鲜牛肉和大肠杆菌O157:H7作为研究对象,监测其在4、16、25、30、37℃贮藏温度条件下进口生鲜牛肉中大肠杆菌生长数据,绘制生长曲线,采用修正Gompertz、Logistic、Richards、MMF四种模型进行拟合,建立进口生鲜牛肉中大肠杆菌一级模型,将一级模型拟合的数据代入Ratkowsky方程建立二级模型,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。结果表明,四种模型拟合后得到的相关系数均为0.98以上,修正Gompertz模型数据表明该模型拟合程度最好,最适合预测大肠杆菌在进口生鲜牛肉上的生长动态,模型的准确因子均为0.99,偏差因子为1.14和1.03,决定系数R~2为0.97和0.99,说明所建立的模型可靠性较高。本研究建立的生长预测模型能够有效预测4~37℃不同温度条件下大肠杆菌O157:H7在进口生鲜牛肉上的生长情况。

In order to establish the growth prediction model of Escherichia coli O157:H7 in imported fresh beef at different temperatures.Fresh imported beef purchased from supermarkets and Escherichia coli O157:H7 were selected as the research objects.The growth data of Escherichia coli in imported fresh beef stored at 4,16,25,30 and 37℃were monitored and the growth curve was drawn.Four models of modified Gompertz,Logistic,Richards and MMF were used to fit the growth curve,and the first-order model of Escherichia coli in imported fresh beef was established.The data fitted by the first-order model was substituted into Ratkowsky equation to establish the second-order model.The accuracy of the model was tested by the accuracy factor,bias factor and root mean square error.Results showed that,the correlation coefficients of the four models were all above 0.98.The data of modified Gompertz model showed that the fitting degree of the modified Gompertz model was the best,and it was most suitable to predict the growth dynamics of E.coli in imported fresh beef.The accuracy factors of the models were 0.99,the bias factors were 1.14 and 1.03,and the determination coefficients R~2 were 0.97 and 0.99,indicating that the established model was highly reliable.The growth prediction model established in this study could effectively predict the growth of Escherichia coli O157:H7 in imported fresh beef at 4~37℃.