即食牛乳中沙门氏菌生长模型的建立

Establishment of a predictive growth model for Salmonella in ready-to-eat sterile milk

为建立即食牛乳中沙门氏菌的生长预测模型,本研究测定了即食牛乳中沙门氏菌在8、15、20、25、30、37、42、47℃和50℃下的生长数据,进而利用Baranyi&Roberts方程和Cardinal方程为基础来建模。结果表明,以Baranyi&Roberts方程为基础来建立生长一级模型,数据拟合效果较好(R2>0.99,RMSE<0.26 Log10 cfu/m L);以Cardinal方程为基础来建立二级模型,数据拟合效果亦较好(R2>0.99,RMSE=0.03 h-1)。此外,通过外部验证,比对即食牛乳中沙门氏菌在27℃和35℃下的模型预测值与试验实测值,验证了所建模型的可靠性(预测值误差<5%)。表明所建预测模型能较好地描述沙门氏菌的生长动态,从而为有效监控即食乳品中沙门氏菌污染提供了理论依据。

The main objective of this study was to develop the primary and secondary models to describe the Salmonella in ready-to-eat sterile milk. The growth data of Salmonella in ready-to-eat sterile milk were collected at different temperatures （8, 15, 20, 25, 30, 37, 42, 47℃ and 50 ℃）. And the data were fitted using Baranyi ＆ Roberts equation and Cardinal equation to develop the model. The result indicated that the Baranyi ＆ Roberts equation fitted the growth data well, the pseudo R2 values were〉0.99 and RMSE values were〈0.26 Log10 cfu/mL. And the Cardinal equation was also suitable for describing the effect of temperature on the specific growth rate for Salmonella in sterile milk, the pseudo R2 values were〉0.99 and RMSE values were 0.03 h-1. Furthermore, the reliability of the established model was tested by comparing growth data at 27℃ and 35 ℃. The result showed that the established model by study could effectively predict the growth trends in sterile milk, which will provide the useful information for detecting and controlling the contamination of Salmonella in ready-to-eat sterile milk.