大豆磷脂对牛乳蛋白乳状液热稳定性的影响

Effect of soybean phospholipid on the heat stability of milk protein emulsions

研究了大豆磷脂对牛乳蛋白乳状液热稳定性的影响,并对相关作用机理进行了探讨。测定了添加磷脂前后牛乳蛋白乳状液的热凝固时间(HCT)、粒径分布、表面疏水性、Zeta电位和游离巯基含量的变化。结果表明:添加大豆磷脂能够提高牛乳蛋白乳状液的热稳定性,其中添加量为2.5 g/L时热稳定性最高,最大HCT为23.49 min。大豆磷脂可能通过与乳蛋白发生疏水相互作用改变蛋白的构象、增加乳状液的负Zeta电位、抑制巯基氧化或降低游离巯基之间的反应几率来提高乳状液的热稳定性。

Effect of soybean phospholipid on the heat stability of milk protein emulsions was studied and the related mechanisms were discussed.The heat coagulation time（HCT）,particle size distribution,surface hydrophobicity,Zeta potential and the content of free sulfhydryl groups of the emulsions adding soybean phospholipid or not were examined.The results showed that soybean phospholipid could enhance the heat stability of milk protein emulsions.The max HCT was 23.49 min when the addition amount of soybean phospholipid was 2.5 g/L.Soybean phospholipid may enhance the heat stability of milk protein emulsions by hydrophobic interaction with milk proteins to change the protein conformation,in-creasing the negative Zeta potential,inhibiting thiol oxidation or decreasing the reaction probability among free sulfhydryl groups.