冻藏条件下高白鲑肌肉蛋白质的生化特性

Biochemical properties of muscle protein from Coregonus peled during frozen storage

以肌肉基本营养成分、蛋白质组成、肌原纤维蛋白Ca^(2+)-ATPase活性、总巯基含量、羰基含量及表面疏水性作为测定指标,考察高白鲑在冻藏过程中的肌肉蛋白质的变化规律。结果显示:高白鲑蛋白质含量为(18.95±0.12)%;随着冻藏时间的延长,肌原纤维蛋白、肌浆蛋白及肌基质蛋白含量均逐渐减少,其中肌原纤维蛋白含量变化最大,由初始值35.86%下降至4.13%,而碱溶性蛋白含量逐渐增加,由初始值19.14%增加至23.74%;肌原纤维蛋白Ca^(2+)-ATPase活性随冻藏时间的增加而降低,冻藏结束时,Ca^(2+)-ATPase活性为0.075μmol Pi/mg protein/min,比冻藏开始时降低了72.8%;总巯基含量随冻藏时间延长逐渐减少,整个冻藏周期呈现两段式下降,冻藏前期下降迅速,后期下降缓慢;羰基含量随冻藏时间的延长不断增加,前2周增加迅速,由初始的4.17 nmol/mg protein增加至4.93 nmol/mg protein;随着冻藏时间的延长,高白鲑肌原纤维蛋白表面疏水性逐渐增大。综合各指标的变化情况,表明随着冻藏时间的延长,高白鲑肌肉蛋白质变性加剧。为研究鱼肉蛋白质在冻藏过程中变化规律提供理论参考。

In order to explore the changes of muscle proteins from Coregonus peled during frozen storage, muscle basic nutrients, protein composition, Ca^（2＋）-ATPase activity of myofibrillar protein, total sufhydryl content, carbonyl contentand and surface hydrophobicity as the measurement index. The results showed that the muscle of Coregonus peled proteincontent as high as（18.95±0.12）%. With the extension of storage time, the content of a decrease trend in myofibrillar protein, myogen and muscle matrix protein decreased and the biggest change was myofibrilar protein content, reducing from the initial value 35.86% to 4.13%. While the content of alkali-soluble protein gradually increased from 19.14% to 23.74%. Ca^（2＋）-ATPase activity of myofibrillar protein showed a trend of decrease. At the end of the frozen, Ca^（2＋）-ATPase activity was 0.075 μmol Pi/mg protein/min, which decreased by 72.8% compared with the starting frozen state. With the extension of storage time, the content of total sufhydryl decreased, in the whole frozen period two sections of a downward trend presented, the early stage of the frozen it dropped rapidly at first and fell slowly in the late. Carbonyl content showed a trend of continuous increase, and at the first 2 weeks increased rapidly, from the initial 4.17 nmol/mg protein increased to 4.93 nmol/mg protein. And the change of surface hydrophobicity showed an increased trend. Comprehensive analysis of the change of the indexes, the denaturation of proteins was enhanced due to the extension of storage time. Our research provided theoretical reference for the study of fish protein change law in the process of frozen storage.