Abstract: Colostrum whey was prepared from defatted bovine colostrum using acid precipitation of casein. Based on acid type and strength and changes in IgG activity, the optimal conditions for acid precipitation of casein were determined as follows: defatted milk was adjusted with 0.8 mol/L lactic acid to pH 4.3 and diluted with water to a dry matter concentration of 10% followed by heating in 45 ℃ water bath for 15 min and centrifugal separation at 4000 r/min for 5 min. Only 3.05% of the IgG activity was found for the prepared whey.

Key words: colostrum；whey；casein

摘要： 为优化乳清制备工艺，以脱脂牛初乳为原料，研究通过酸沉酪蛋白方法制备高质量乳清。综合考虑酸的种类、强弱和乳清中IgG的活性变化，确定了酸沉酪蛋白的最佳工艺条件为：0．8mol／L乳酸调脱脂乳pH值至4．3，加水至干物质终质量分数为10％，45℃水浴15min，4000r／min离心5min。经检测所制备的乳清中IgG活性含量仅损失3．05％。

关键词: 牛初乳; 乳清; 酪蛋白