中国水牛乳中α-乳白蛋白活性分离方法比较
Comparison of methods for the isolation of active α-lactalbumin in Chinese buffalo milk
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摘要: 以水牛乳为原料,离心分离脂肪,再采用等电点缓慢酸沉去除酪蛋白,结合铁盐沉淀法和钙盐沉淀法两种方法分别对乳清蛋白中α-乳白蛋白进行活性分离,在保证α-乳白蛋白分离纯度的同时,对其活性和得率分析检测。结果显示,铁盐沉淀法分离α-乳白蛋白时,在pH4.54.7的酸性条件下采用质量分数0.04%的铁盐分离α-乳白蛋白保证α-乳白蛋白纯度达到电泳纯的同时,其活性比例和得率分别达到44.68%和21.06%;而在pH7.0的中性条件下采用质量分数0.005%的铁盐分离α-乳白蛋白也可保证α-乳白蛋白的纯度达到电泳纯,此时,其活性比例和得率分别达到64.00%和13.23%。钙盐沉淀法可很好地保持α-乳白蛋白的活性,但分离纯度过低。Abstract: With methods of fat centrifugal separation, isoelectric precipitation, iron salt precipitation and calcium precipitation, the α-lactalbumin in Chinese buffalo milk was isolated, and its activity and recovery were analyzed, while keeping the purity.When the purity of the isolatedα-lactalbumin exceeded 90%, its activity ratio and recovery reached to 44.68% and 21.06% respectively, by the use of 0.04% iron salt at pH4.5~4.7.While the referred activity ratio and recovery were 64.00% and 13.23% respectively with the use of 0.005% iron salt at pH7.0.Calcium salt precipitation gave a pretty high activity ratio of α-lactalbumin, but it brought the problem of a low purity, which made it deprecated to isolate the α-lactalbumin that demanding higher purity in active isolation.