温度、pH和盐对乳清蛋白乳状液稳定性的影响

Influence of temperature,pH and salts on the stability of emulsions stabilized by whey protein

乳清蛋白具有一定的乳化能力，在食品工业中常作为乳化剂使用，以乳清浓缩蛋白（WPC）、乳清水解蛋白（WPH）和乳清分离蛋白（WPI）为乳化剂，经高压均质制备O／W型乳状液，以平均粒径和分层系数为稳定性指标．研究了温度、pH和盐对乳状液稳定性的影响。结果表明：WPI乳状液具有最小的平均粒径。各环境因素对乳状液稳定性的研究表明，pH是影响乳状液稳定性最显著的因素，当pH在蛋白质等电点（4～6）附近时，各乳状液中粒子均发生絮凝或聚合，乳状液发生脱稳。受环境因素影响，WPC乳状液具有最好的稳定性。这些结果为乳清蛋白作为乳化剂用于食品工业提供了重要依据．

Whey protein has certain emulsifying ability in the food industry, often used as emulsifiers.Whey protein concentrate（WPC） ,whey protein hydrolysate（WPH）and whey protein isolate（WPI）were as emulsifier to prepare O/W emulsion by high pressure homogenization.With average particle size and layered coefficient as stability index,effects of temperature, pH and salt on emulsion stability were studied.pH was the most Significant factor.Appreciable droplet flocculation occurred near the isoelectric point of whey protein （pH4-6）.Near the isoelectric point of pH4-6, particles in emulsion occurred flocculation or aggregation to become unstable.WPC had the best stability of the emulsion.These results provided an important basis for the whey protein as an emulsifier for the food industry.