不同种类糖对酪蛋白糖基化接枝改性的影响

Effects of different kinds of sugars on grafting modification for casein glycosylation

该文探究了酪蛋白糖基化接枝改性与改性糖种类选择的关系。选取8种聚合度和结构差异糖与酪蛋白湿法糖基化接枝改性,对其产物进行分析研究。结果表明,醛糖中分子质量较小的葡萄糖更易与酪蛋白糖基化接枝(P<0.05),接枝度显著高于酮糖(P<0.05)。酪蛋白与麦芽糖、葡聚糖20 000和40 000的接枝产物具有良好接枝度和抗脂质氧化能力,乳化活性较酪蛋白分别显著提高30.14%,42.47%和52.05%(P<0.05);静置15 min乳化稳定性良好(P<0.05)。在15 min内,酪蛋白乳化活性线性下降,而酪蛋白-葡聚糖40 000共价接枝物乳化稳定性较酪蛋白提高85.91%。酪蛋白与葡聚糖或麦芽糖糖基化接枝改性高效易行,具有良好的抗脂质氧化能力和乳化特性,对酪蛋白糖基化改性进一步研究、酪蛋白及糖类的开发应用、及其营养价值提升有积极作用。

In order to investigate the relationships between glycosylation graft modification of casein and modified sugar types and improve the selection specificity,eight types of sugars with different polymerization degrees and structures were selected for modification of casein by wet glycosylation.The results showed that glucose could glycosylate with casein efficiently(P<0.05),and the grafting degree was significantly higher than other ketoses(P<0.05).The grafted products of casein with maltose,dextran 20 000 and dextran 40 000 had desirable grafting degree and anti-lipid oxidizing ability,and their emulsifying activity significantly increased by 30.14%,42.47%and 52.05%,respectively,in comparison to casein(P<0.05).Moreover,their emulsion stability has no significant change after standing for 15 min(P<0.05).In particular,the emulsification activity of casein decreased linearly within 15 min,while the emulsion stability of casein-dextran 40 000 covalent graft increased by 85.91%comparing with casein.Graft modification of casein with glucan or maltose glycosylation is more efficient and facile.And it has good anti-lipid oxidation and emulsifying properties This study can promote further study on casein glycosylation modification,the development and application of casein with sugars and also enhancing their nutritional value.