酶解时间对大豆蛋白-溶血磷脂相互作用及乳化特性的影响

通过不同酶解时间得到大豆溶血磷脂,对大豆分离蛋白-溶血磷脂相互作用及其对复合乳化体系乳化特性的影响进行探究,采用荧光光谱法在Stern-Volmer和Van’t Hoff方程基础上对大豆分离蛋白-溶血磷脂荧光猝灭作用、相互结合常数、结合位点及相互作用力类型进行判断,并对复合乳化体系分别进行乳化活性、乳化稳定性的测定及微观结构变化的观察。结果表明:随着磷脂酶A1酶解时间的延长,大豆分离蛋白-溶血磷脂相互作用先增强后下降,乳化特性指标同样基本呈现先升高后降低的趋势,这表明二者的相互作用对乳化特性具有一定影响。其中,当酶解时间为4 h时,二者相互作用最强,乳液的乳化特性表现最佳,这表明适度酶解产生的溶血磷脂会促进其与大豆分离蛋白的相互作用,在水油界面上形成较稳定的界面膜,形成稳定的复合乳状液。

Effect of Enzymatic Hydrolysis Time on Emulsifying Properties and Interaction of Soybean Protein Isolate-Lysophospholipid Emulsion

In this work, we explored the effect of enzymatic hydrolysis time for preparing lysophospholipid on the interaction between soybean protein isolate (SPI) and lysophospholipid (LP) and the emulsifying properties of an SPI-LP composite emulsion system. Fluorescence quenching, binding sites and constant and interaction forces between SPI and LP were investigated based on the Stern-Volmer and Van’t Hoff equations by fluorescence spectroscopy. Furthermore, the emulsifying activity and stability were determined, and the microstructural change of emulsion was observed. The results showed that as the hydrolysis time by phospholipase A1 was prolonged, the interaction between SPI and LP first increased and then decreased, and so did the emulsifying properties, which suggested that the interaction had some effects on the emulsifying properties. Among five hydrolysis times tested, 4 h hydrolysis demonstrated the strongest interaction between SPI and LP and the best emulsifying properties indicating that lysophospholipid produced by moderate hydrolysis showed improved interaction with SPI to form a stable interfacial film at the water-oil interface for stable composite emulsion.