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

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 R² 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 coliO157:H7 in imported fresh beef at 4~37 ℃.