冻生虾仁金黄色葡萄球菌预测模型的建立及应用

Establishment and application of predictive growth model of Staphylococcus aureus in the frozen fresh shelled shrimp

为得到生虾仁中金黄色葡萄球菌的生长模型,以期对加工中遭受金黄色葡萄球菌污染后的增长状况进行预测,通过把金黄色葡萄球菌接种到生虾仁,按生产工序拟定四个温度(4、10、13、20℃)并测定该菌在不同温度下菌落数的变化,采取3种常用方程进行拟合,比较后得出各温度的最适一级生长模型,并建立二级模型。结果表明,10、20℃适合采用Gompertz模型,13℃为Logistic模型,4℃采用Linear模型;预测表明金黄色葡萄球菌在解冻工序增长较明显,增长率9.7%;采用平方根方程拟合得到二级预测模型:umax=0.0129T-0.0220;模型验证表明预测值和实测值的残差在±0.01内,偏差因子和准确因子在可接受范围内,表明模型有效,用于生产预测,具有一定参考价值。

This paper was aimed to establish the growth model of Staphylococcus aureus in the frozen shelled shrimp,in order to predict the growth of Staphylococcus aureus in the shrimps during processing. Inoculations of Staphylococcus aureus to the frozen shelled shrimps were carried out. According to the actual situation of the process, four different temperatures （4, 1 0,13,20 ℃） were selected to determine the Staphylococcus aureus growth in frozen shelled shrimp. Two kinds of equations were used to fit the data which result in the optimum primary growth models after comparison, thus established the secondary growth model. The fitting results showed that Gompertz equation was best for 10℃ and 20℃growth model, Logistic equation was best for 13~C growth model, linear equation was adopted for 4℃. Predictions in processing by models indicated that obvious growth of Staphylococcus aureus could be found in the processes of unfreezing,the growth rate were 9.7%.The square root equation was adopted to get the secondary predictive model=/umax = 0.0129T-0.0220.Model validation showed that the residual errors of predicted value and measured value were within ＋ 0.01, factors of deviation and accuracy were in acceptable range.The model possessed good dependability that can be useful for microbe prediction in processing.