牛乳中αs、β-酪蛋白组分的分离

以新鲜脱脂牛乳为原料，在碱性条件下添加钙盐进行选择性沉淀分离αs-、β- 酪蛋白组分，并用十二烷基磺酸钠- 聚丙烯酰胺凝胶电泳(SDS-PAGE)法测定分离效果。从CaCl2 溶液终浓度、冷却温度和反复溶解﹑沉淀次数三个方面对αs-、β- 酪蛋白的分离效果进行研究。结果表明：CaCl2 溶液终浓度0.065mol/L，冷却温度2℃，经3 次反复溶解﹑沉淀，分离得到的αs- 酪蛋白组分纯度较高，可达83.33%，β- 酪蛋白组分纯度为109.53%。

Separation of αs- and β-Caseins from Milk

Selective precipitation of αs- and β-caseins from skimmed milk was achieved by the addition of calcium salt at alkaline pH. Effects of final concentration of CaCl2 (adding different volumes of 0.5 mol/L CaCl2 solution to skimmed milk), cooling temperature and repeated dissolution-precipitation procedure times on separation of αs-casein were analyzed by measuring purity of final products using SDS-PAGE followed by Coomassie brilliant blue staining, along with effects of the former two factors on separation of β -casein. The results showed that αs-casein with a purity of 83.33% and β -casein with a purity of 109.53% could obtained when the final concentration of CaCl2 was 0.065 mol/L, the cooling temperature 2 ℃, and the dissolutionprecipitation procedure repeated three times.