脱脂牛乳体系中乳蛋白葡萄糖美拉德反应程度及产物功能性质研究

以脱脂牛乳为研究对象,以葡萄糖为还原糖,对乳蛋白进行美拉德反应修饰,研究葡萄糖添加量为0~9 g/100 mL脱脂乳时反应体系的糖基化程度、pH、中间产物含量、褐变程度、粒径,以及产物乳化性、发泡性和吸油性。结果显示,脱脂乳体系糖基化程度在葡萄糖添加量为3 g/100 mL时达到最大值,之后迅速降低;中间产物和褐变程度均在该添加量下达到最低值,之后迅速上升。反应体系pH并未随葡萄糖添加量的增加而显著变化。糖基化反应后,酪蛋白胶束粒径增加。糖基化修饰改善了脱脂乳体系的乳化性,当葡萄糖添加量为3 g/100 mL时,乳化活性和乳化稳定性均达到最大值。糖基化修饰后,脱脂乳体系的发泡性并未显著提高,但该体系10和30 min泡沫稳定显著增加(p<0.05)。糖基化修饰后乳蛋白的吸油性降低。研究结论可为脱脂乳体系中乳蛋白美拉德反应产物的应用提供基础数据。

Maillard Reaction Degree and Product Functional Properties of Proteins-Glucose in Skim Milk System

In this study,glucose was used to modify skim milk through Maillard reaction. The modified degree,pH,intermediate,browning intensity,particle size,as well as product emulsification,foaming and oil absorption of skim milk-glucose system under the addition of glucose with 0~9 g/100 mL skim milk were analyzed. The results showed that the glycosylation degree of skim milk-glucose system increased with the increase of glucose amount and reached the maximum at the glucose addition of 3 g/100 mL skim milk,which decreased afterwards. On the contrary,the amount of intermediate and browning intensity of this system had minimum value at the same glucose addition,which increased afterwards. However,the pH of the system kept stable with the concentration of glucose increased. The particle size of micelles in skim milk increased with modification. After modification through Maillard reaction,the emulsifying activity index and emulsion stability of skim milk increased,and they had maximum value at the addition of 3 g/100 mL. However,the foaming capacity of skim milk did not changed significantly with glycosylation. Interestingly,the foam stability at 10 and 30 min of skim milk increased dramatically(p<0.05)after it was glycosylated by glucose. As to oil absorption of milk protein,it decreased with increase of glucose addition. The results of this research could provide the basic data for the application of the skim milk-glucose Maillard reaction products.