葡萄糖糖基化大豆分离蛋白的凝胶抗冻性研究

Antifreeze Capacity of Glucose Glycosylated Soybean Protein Isolate Gel

为解决大豆蛋白在冷冻食品中因冷冻变性导致功能性下降的问题,本研究对大豆分离蛋白进行了葡萄糖糖基化改性,并分析了改性大豆分离蛋白凝胶的抗冻性变化。结果表明,葡萄糖改性可以提高大豆分离蛋白凝胶的抗冻性,糖基化改性反应条件为蛋白:葡萄糖=2:1、反应pH 7、蛋白含量为40 mg/g。糖基化改性蛋白制备的凝胶在冻藏过程中的蛋白溶解性、亚基及凝胶水分分布等结果显示,改性大豆蛋白凝胶抗冻性的提高是由于糖基化蛋白中葡萄糖分子增强了对水分子的束缚作用从而减少蛋白质的脱水变性,同时,接枝在蛋白链上糖分子的空间位阻作用,阻止了蛋白分子间聚集和新键的形成,维持凝胶的均匀网状结构。

To solve the problem that the functional quality decreased caused by soy protein denaturation during frozen storage of frozen food, in this study, SPI （soybean protein isolate） was modified with glucose glycosylated modification, and the change of SPI gel antifreeze capacity was analyzed. According to the research results, the antifreeze capacity of SPI gel could be improved by glucose modification, and the glycosylated modified reaction condition was protein： glucose =2： 1, reaction pH =7, the content of protein was 40 mg/g. According to results such as protein solubility, subunits and gel water distribution of gel produced by glycosylated modified protein during frozen storage, it was concluded that the reason why the antifreeze capacity of modified soybean protein gel was improved was that glucose molecule in the glycosylated modified strengthened constraint of water molecules to reduce the dewatering denaturation of protein. Meanwhile, the steric hindrance effect of sugar molecule grafted on the protein chain could stop aggregation among protein molecules and formation of new bond to keep uniform reticular formation