不同贮藏温度下冷却猪肉货架期预测模型的构建

摘要

This study was designed to establish a predictive model for the shelf-life of chilled pork with specific spoilageoorganisms. Pork leg muscles were washed with 80 ℃ sterile water, inoculated with Aeromonas spp., seal-packaged, and stored at 0, 4, 7, 15 or 20 ℃. The values of pH, TVBN and TBA and total viable count were determined during storage at the different temperatures. Besides, sensory evaluation was carried out. The resulting data were analyzed with the software Origin 8.0. The results show that the growth dynamics of A. spp. in chilled pork could be well fitted with a modified Gompertz model. Temperature effect on maximum specific growth rate and lag phase was described by the root-mean-squares (Bĕlehrádek) model as a good linear relationship with R2 values of 0.93 and 0.95, respectively. At the end of organoleptic shelf life, the average logarithmic value (lg NS) of A. spp. number (CFU/g) in pork samples stored at 0, 4, 7, 15 or 20 ℃ was (6.33 ± 0.14)(lg (CFU/g)), and the average value of lg Nmax was(7.36 ± 0.21)(lg(CFU/g)). A shelf life (SL) model for chilled pork stored at 0–20 ℃ was established as follows: SL = [1/(0.026T-0.00048)2]-[(7.36-lgN0)/2.718 × (0.0102T + 0.148)2] × {ln[-ln(6.33-lgN0)/(7.36-lgN0)]-1}. The model was validated by observing the actual shelf-life of pork at 8 ℃ and 12 ℃. The relative errors between the actual and predicted shelf-lives at 8 ℃ and 12 ℃ were both below 10%, suggesting that the predictive model was effective in predicting the shelf-life of chilled pork stored at 0–20 ℃.%建立冷却猪肉中特定腐败菌的货架期预测模型。将气单胞菌接种到经80℃无菌水灭菌的猪精腿肉中，分别密封包装于0、4、7、15℃和20℃温度贮藏，测定各温度下接种猪肉的菌落总数(N)、pH值、TVBN值、TBA值，并进行感官评分。采用Origin8.0分析软件对数据进行处理，结果表明：修正的Gompertz方程能较好地拟合不同温度下气单胞菌的生长动态，应用平方根模型(Bĕlehrádek)描述温度对最大比生长速率(µmax)和迟滞期(Lag)的影响，均表现出良好的线性关系，R2分别为0.93和0.95。猪肉在0、4、7、15℃和20℃温度下气单胞菌的感官货架期终点菌数对数平均值为(6.33±0.14)(lg(CFU/g))，平均最大菌数对数为(7.36±0.21)(lg(CFU/g))，得到在0～20℃贮藏温度下冷却猪肉的货架期预测模型为SL=[1/(0.026T－0.00048)2]－[(7.36－lgN0)/2.718×(0.0102T+0.148)2]×{ln[－ln(6.33－lgN0)/(7.36－lgN0)]－1}。通过8℃和12℃贮藏温度下冷却猪肉的货架期实测值对构建的预测模型进行验证，相对误差均小于10%，表明建立的模型可以有效地预测冷却猪肉在0～20℃贮藏温度下的货架期。