不同包装条件下冷却猪肉品质特征指标及动态模型研究

研究冷却肉在不同包装条件下的品质变化及建立微生物预测模型进行预报。将冷却肉用托盘、真空和气调包装的方式放置4、7℃和10℃条件下贮藏，分别测定不同贮藏时间的色差L* 值、pH 值、TVBN 值和细菌总数。结果表明：L* 值和pH 值先降低后升高，而TVBN 值和细菌总数持续增高，且不同包装差异明显；以Gompertz方程为基础，结合模型建立组的数据，通过Matlab 软件拟合与统计学运算确定修正后的微生物生长方程为lgN=lgNo＋ Aexp{－ exp[－ B(t －M)]}。通过模型检验组数据的模型置信度和二级模型验证，证明所建立的模型能较为准确的拟合出微生物生长的真实情况，具有可靠性和通用性。最终确立货架期公式：货架期/d={[lg(MSL)－ lg(No)]× ln10}/(U × 24)＋ LPD。

Characteristic Index and Dynamic Model of Chilled Pork under Different Package Conditions

In order to explore the quality change and establish prediction model of microorganisms in chilled pork under different package conditions, the values of L*, pH, TVBN value and total microorganism counts of chiller pork under pallet, vacuum and modified atmosphere packaging were determined during the storage at 4, 7 ℃and 10 ℃. Results showed that the value of L* and pH exhibited an initial decrease and a final increase; however, the TVBN value and microorganism counts exhibited a gradual increase. In addition, an obvious difference of these characteristics was observed in different package conditions. Based on Gompertz equation and experimental data, a growth equation for microorganisms was established to be lgN=lgN0+Aexp{－exp [－B(t－M)]} with the aid of Matlab software. Through the verification using the secondary model and confidence of tested data, the establish model could precisely describe the growth of microorganisms with higher reliability and versatility. Finally, a prediction model of shelf-life have also been established to be shelf-life (d) = {[lg(MSL)－lg(N0)]×ln10}/(U×24)＋LPD.