枸杞牛乳肽酒制备工艺优化及其抗氧化性分析

Optimized Preparation and Antioxidant of Wine from Milk Protein Hydrolysates Added with Chinese Wolfberry Juice

为克服传统白酒功能性、营养性不足的缺陷,以脱脂牛乳和枸杞为材料,采用对比及正交试验,对乳蛋白酶解条件、枸杞牛乳肽酒的制备工艺和抗氧化功能进行了研究。结果表明:1)胰蛋白酶是水解牛乳蛋白的最佳蛋白酶;2)胰蛋白酶的最佳酶解条件是在pH 7.0、温度40℃、加酶量4 500 U/g的条件下酶解120 min;3)枸杞牛乳肽酒的最佳发酵工艺:以牛乳蛋白酶解液为载体,添加体积分数14%枸杞汁、7.5%的活化酵母菌液,28℃发酵9 d。制备的枸杞牛乳肽酒具有较高的体外抗氧化活性,且香味协调,口感良好,其感官指标和理化指标都符合并高于国家发酵型甜奶酒的标准。

In an effort to overcome the functional and nutritional deficiencies of traditional Chinese liquor,wine was prepared from milk protein hydrolysates added with Chinese wolfberry juice.First of all,milk protein hydrolysates were prepared by enzymatic hydrolysis of skim milk and different proteases were compared in terms of sensory and chemical properties of hydrolysates for this purpose.Then,the hydrolysis process and the fermentation process were optimized using an orthogonal array design method.Besides,the antioxidant activity of the wine was assessed.The results obtained were as follows:1)trypsin was the best protease for hydrolyzing milk protein;2)the optimal conditions for enzymatic hydrolysis were120min hydrolysis at pH7.0and40℃with an enzyme dose of4500U/g;and3)the optimum fermentation conditions were addition of14%(V/V)Chinese wolfberry juice to milk protein hydrolysates,which were then fermented at28℃for9days.The wine exhibited high antioxidant activity in vitro,having a harmonious aroma and a good taste.Moreover,its sensory and physicochemical indicators could meet or exceed the national standard of fermented sweet milk wine.