冷却牛肉贮藏过程中易受微生物的污染,通过建立微生物数学模型,可以预测冷却牛肉的污染情况。实验以自然污染下的冷却牛肉为介质,对0、4、7、10、15、20℃恒温条件下的菌落总数进行计数,利用SAS软件拟合Modified Compertz方程,并对比生长率和时间拟合了平方根二级模型,最后在波动温度下对模型进行了验证。结果显示,Modified Compertz方程能很好地反映冷却牛肉中菌落总数的污染情况,恒定温度下的模型拟合度都在0.95以上,对波动温度条件下的菌落总数的预测值与实测值进行比较,偏差度为0.90,准确度为1.12,表明菌落总数生长模型可以可靠地预测冷却牛肉的微生物污染情况。

【Objective】In order to predict the quality of chilled beef,the mathematical model should be established.【Method】This study was performed to develop predictive models for total plate count(TPC) in chilled beef during several constant temperatures(0℃,4℃,7℃,10℃,15℃ and 20℃) and the second model was established between specific growth rate and time.The validation of predictive models on the fluctuant temperature was analyzed.【Result】 The results showed that mathematical models were obtained at different temperatures with experimental data and fitted into modified Gompertz model with a high correlation coefficient(R2>95%).Comparing predictive data with experimental data during fluctuant temperature,bias factor of 0.90 and accuracy factor of 1.12 were all in the acceptable range.【Conclusion】 This demonstrated that growth models of TPC can predict the microbial quality of chilled beef.