冷却猪肉中小肠结肠炎耶尔森氏菌生长动力学模型的建立和评价

将特定的小肠结肠炎耶尔森氏菌(以下简称耶氏菌)接种到无污染的冷却猪肉表面,托盘包装后分别在0、5、10和15℃条件下贮藏,将不同温度下得到的耶氏菌生长实验值用于建立其生长动力学模型,结果表明修正Gompertz方程能很好地描述耶氏菌在冷却猪肉中的生长动态。lgNmax(最大菌数)受贮藏温度的影响不大,在4种温度下平均值为9.259±0.83(log10cfu/g)。温度对μmax(最大比生长速率)和Lag(延滞时间)的影响,采用平方根模型(Belehradek)描述呈现良好线性关系。用贮藏在3℃、8℃下耶氏菌的生长实验值验证建立的模型,偏差度分别为0.92、0.97,准确度分别为1.09、1.04,表明所建立的耶氏菌生长动力学模型的可靠性很好。

Construction and Assessment of Microbial Growth Kinetics Prediction Model of Yersinia enterocolitica in Chilled Pork

The no contamination longissimus muscle was inoculated by Yersinia enterocolitica,and then was tray-packaged at 0,5,10 and 15℃ for storage.A series of experiments had been carried out to develop and validate the growth kinetics model of Yersinia enterocolitica.The results showed that growth dynamics of this organism at different temperatures could be well described by Gompertz model.The temperature had no significant effect on lgNmax(maximum cell concentration),the average value of lgNmax was determined to be 9.259±0.83(log10cfu/g) at above four temperatures.The correlation regression of Blehradek model finely described the influence of temperature on growth.Validation of built kinetic model was carried out by comparing with experimental development of Yersinia enterocolitica grown on chilled pork at temperatures 3℃,8℃.Bias and accuracy factors were used as comparative indices,which were 0.92,0.97 and 1.09,1.04,respectively.It suggested the growth kinetics model of Yersinia enterocolitica was reliably.