乳源抗菌肽复合生物保鲜剂对冷却牛肉货架期的影响

Effects of Composite Biological Preservatives Containing Antimicrobial Peptides Derived from Casein on the Shelf-Life of Chilled Beef

为延长冷却牛肉货架期并建立货架期预测模型,选取乳源抗菌肽、壳聚糖、乳酸链球菌素(Nisin)、茶多酚和丁香精油5种天然保鲜剂,通过U16(84)均匀试验,以挥发性盐基氮(total volatile basic nitrogen,TVB-N)含量、pH值和菌落总数为指标进行分析,确定保鲜剂的适宜添加量为壳聚糖22.5 g/L、Nisin 0.15 g/L、乳源抗菌肽9.7 g/L、茶多酚1.5 g/L、丁香精油13.0 g/L,(4±1)℃条件下冷却牛肉货架期比空白组延长了25 d以上。对于冷却牛肉TVB-N含量,乳源抗菌肽与Nisin、茶多酚、丁香精油之间及Nisin与茶多酚之间具有极显著的交互影响(P<0.01),丁香精油与Nisin之间具有显著的交互作用(P<0.05)。用复合天然保鲜剂处理后的冷却牛肉在-1、2、6℃条件下贮藏,运用Arrhenius方程拟合温度对冷却牛肉菌落总数的影响,结果显示不同温度下决定系数R2均大于0.91,货架期预测模型为SL=2.75×10-9×exp(6 567.2/T)。贮藏温度分别为2、4℃和6℃时,冷却牛肉的实际货架期分别为61、53 d和47 d,与货架期预测值相比,相对误差均在6%以内,表明建立的模型可以有效预测冷却牛肉在-1～6℃贮藏条件下的货架期。

In order to extend the shelf-life of chilled beef and establish a predictive model for the determination of the shelflife,we developed and optimized an effective composite preservative containing antimicrobial peptides derived from casein,chitosan,nisin,tea polyphenols and clove essential oil using a U16(8^4)uniform design.Total volatile basic nitrogen(TVB-N)value,pH and total viable count were used as response variables.The results showed that the optimal combination was determined as22.5g/L chitosan,0.15g/L nisin,9.7g/L antimicrobial peptides derived from casein,1.5g/L tea polyphenols and13.0g/L clove essential oil.Compared with the control group,the shelf-life of chilled beef treated with the optimal composite preservative and stored at(4±1)℃was extended by over25days.The interaction between antimicrobial peptides and nisin,tea polyphenols or clove essential oil,and between nisin and tea polyphenols had a significant effect on the change of TVB-N content(P<0.01).Total viable counts of chilled beef treated with this composite preservative as a function of storage temperature(-1,2and6℃)were fitted with the Arrhenius equation with the coefficients of determination greater than0.91.The shelf-life(SL)prediction model developed was as follows:SL=2.75×10^-9×exp(6567.2/T).The actual shelf-life of chilled beef at2,4and6℃was61,53and47d,respectively and the relative error between the actual and predictive values less than6%,suggesting that the model can effectively predict the shelf-life of chilled beef at-1–6℃.