基于预测微生物学的冷却牛肉货架期预测模型的建立

Predictive Modelling for Shelf-Life Determination of Chilled Beef Based on Predictive Microbiology

为实时监测冷却牛肉贮藏期间的品质变化与货架期,分别测定冷却牛肉0、4、7、10℃贮藏过程中假单胞菌菌数、总挥发性盐基氮含量和感官评分。利用修正的Gompertz方程建立不同贮藏温度下假单胞菌生长的动力学模型,以Belehradek方程为二级模型,描述贮藏温度对假单胞菌生长的影响,并利用2、5、8℃条件下贮藏的冷却牛肉验证货架期预测模型的准确性。结果表明:所建立的Gompertz模型拟合相关系数均在0.99以上,预测结果准确度在1.013~1.126之间,偏差度在0.926~1.057之间,贮藏温度与μmax^1/2和(1/λ)^1/2均呈良好的线性关系,说明建立的一级和二级模型能够真实、有效地预测0~10℃贮藏条件下冷却牛肉中假单胞菌的生长情况;货架期的预测值与实测值相对误差在±10%以内,该货架期模型可有效预测冷却牛肉在0~10℃贮藏条件下任意温度下的货架期。

In order to monitor the quality change and shelf-life of chilled beef during storage, the number of Pseudomonas, total volatile basic nitrogen content and sensory score of chilled beef during storage at 0, 4, 7 or 10 ℃ were measured. The growth data of Pseudomonas were fitted to the modified Gompertz equation. The Belehradek equation was used as a secondary model to describe the influence of storage temperature on the growth of Pseudomonas. The accuracy of the shelflife prediction model was verified by applying it on chilled beef stored at 2, 5 or 8 ℃. The results showed that the correlation coefficients of the Gompertz model established were all above 0.99. The accuracy of the prediction results ranged from 1.013 to 1.126, and the deviation degree from 0.926 to 1.057. There was a good linear relationship between storage temperature and μmax^1/2 and(1/λ)^1/2, indicating that the primary and secondary models could accurately predict the growth of Pseudomonas in chilled beef at 0–10 ℃. The relative error between the predicted and measured values of shelf-life was within ± 10 %. The model could effectively predict the shelf-life of chilled beef at temperatures from 0 to 10 ℃.