冷藏和冻藏对牦牛瘤胃平滑肌氧化稳定性及加工品质的影响

为探明4℃冷藏和-18℃冻藏对牦牛瘤胃平滑肌脂肪和蛋白质氧化及其加工特性的影响,以PE薄膜和PE真空包装的牦牛瘤胃为研究对象,分别测定其在贮藏过程中的脂肪氧化(硫代巴比妥酸)、蛋白质氧化(羰基值、总巯基、表面疏水性)和加工品质(失水率、蒸煮损失率、剪切力、质构特性)的变化。结果表明,不同贮藏温度和包装方式下的瘤胃均发生了不同程度的脂肪和蛋白质氧化,与薄膜包装相比,真空包装可延缓牦牛瘤胃脂肪和蛋白质氧化的发生,且-18℃冻藏下更为显著。此外,冷(冻)藏条件下不同包装牦牛瘤胃的失水率和蒸煮损失率均显著增大(P<0.05),剪切力值显著降低(P<0.05),硬度先减小后增大,且薄膜包装在冷藏0~5 d和冻藏0~28 d时,其加工特性均优于真空包装。综上表明,2种包装下的牦牛瘤胃在冷(冻)藏过程中均发生了脂肪和蛋白质氧化,但真空包装可以有效地延缓氧化反应的发生。此外,在冷藏0~5 d和冻藏0~28 d时,薄膜包装更有利于改善瘤胃的加工特性,增加其嫩度和弹性,但长时间贮藏会导致瘤胃加工特性下降,冷藏条件下薄膜包装瘤胃的变化表现最为显著。本研究可为瘤胃贮藏过程中食用品质的控制提供参考。

Effects of Chilled Storage and Frozen Storage on OxidativeStability and Processing Quality of Yak Rumen Smooth Muscle

In order to find out the effects of 4℃ chilled storage and -18℃ frozen storage on rumen smooth muscle lipid and protein oxidation and processing characteristics of yak, the yak rumen of PE film and PE vacuum packaging were used as research objects to determine their lipid oxidation (thiobarbituric acid), protein oxidation (carbonyl, total sulfhydryl, surface hydrophobicity) and processing quality (pressure loss rate, cooking loss, shear force, texture characteristics) during storage. The results showed that different degrees of lipid and protein oxidation occurred in the rumen under different storage temperatures and packaging methods. Compared with film packaging, vacuum packaging can delay the occurrence of yak rumen lipid and protein oxidation, and -18℃ frozen storage to be more significant. In addition, under the condition of chilling (freezing) storage, the pressure loss rate and cooking loss rate of yak rumen in different packaging yak were significantly increased (P<0.05), the shear force was decreased significantly (P<0.05), and the hardness was decreased first and then increased. The processing quality of film packaging was better than vacuum packaging when they were stored for 0-5 days in chilled and 0-28 days in frozen storage. In summary, during chilling (freezing) storage, the lipid and protein oxidation occurred in the yak rumen under the two packaging methods, but vacuum packaging can effectively delay the occurrence of oxidation reaction. Furthermore, when chilled for 0-5 days and frozen for 0-28 days, the film packaging was more beneficial to improve the rumen processing quality and increase its tenderness and springiness. But long-term storage will lead to a decline in rumen processing characteristics, and the rumen changes of film packaging were the most significant under chilled conditions. The results of this study can provide a reference for the control of food quality during rumen storage.