共沉淀乳蛋白的制备条件优化与产品功能性评价

Study on optimal preparation conditions for co-precipitated milk proteins and functionality of products

采用共沉淀的方法从牛乳中制备共沉淀乳蛋白,并对产品进行组成和功能性的评价。确定制备共沉淀乳蛋白的最佳工艺条件为pH值为6.5,CaCl2质量分数0.2%,加热温度100℃,加热时间20 min。此条件下乳蛋白回收率超过93%。成分分析表明,共沉淀乳蛋白中含有乳清蛋白,总蛋白质质量分数超过90%。功能性评价结果表明共沉淀乳蛋白的胶凝性和乳化性优于酪蛋白,但保水性低于酪蛋白,表明其可以作为一种食品配料。

Co-precipitated milk protein products were prepared from skim milk by a co-precipitation method with CaCl2. The chemical compositions and three important functionalities of the products obtained were evaluated. The optimal preparation conditions for co-precipitated milk proteins were as follow： CaCl2 addition level was about 2.54%, pH was adjusted to 6.5, skim milk was heated at 100℃ for 20 min. With these parameters, co-precipitated milk protein products obtained contained whey proteins and total milk protein recovery was more than 90%. It was shown that the gelation property and emulsifying property of co-precipitated milk protein products were superior to that of casein, but water retention capacity was inferior to that of casein. The results showed that co-precipitated milk protein products might suitable as a new food ingredient.