Abstract: In order to investigate the effect of different environmental conditions on the growth rate of Salmonella enteritis, the bacterium was cultured in a liquid medium in this study, and the Baranyi model and cardinal parameter model (CPM were established and evaluated as primary and secondary model, respectively. Temperature (30–42 ℃), pH (6.6–8.0) and water activity (aw, 0.976–0.997) were taken as independent variables to develop the cardinal parameter models and based on the Gamma concept, the independent effects of three environmental conditions were studied. The coefficient of determination was used to evaluate the goodness of fit of the primary model and the secondary models were validated by mathematical test values. The results the experimental data were well fitted with the Baranyi model (R2 > 0.900). The estimated values of Tmax, Topt, pHmax, pHmin, pHopt, aw(min) and aw(opt) were 44.51 ℃, 34.24 ℃, 8.14, 6.09, 7.55, 0.957 and 0.997, respectively. In the external validation with random data in the experimental range investigated, acceptable mean squared error (MSE, 2.311 × 10-5), bias factor (0.963) and accuracy factor (1.267) were obtained. These results indicated that the CPM we developed could accurately predict the growth rate of S. enteritis, which could provide a valuable theoretical basis for reducing the food safety risk caused by S. enteritis.

Key words: Salmonella enteritis, cardinal parameter model, Gamma concept, temperature, pH, water activity