湿法美拉德反应与转谷氨酰胺酶交联对大豆分离蛋白功能性质的影响

摘要

以大豆分离蛋白(SPI)、转谷氨酰胺酶(TG)和3种单糖为原料,模拟湿法美拉德反应和TG酶交联,对SPI进行改性,分析了SPI的游离氨基含量、溶解性和乳化性的变化.结果表明,TG酶交联能促进湿法美拉德反应.3种单糖糖基化反应程度依次为:D-半乳糖＞葡萄糖＞D-果糖.糖基化增加SPI溶解性,TG酶处理降低SPI溶解性,糖基化和TG酶联合作用对SPI溶解性影响不大.糖基化降低了SPI疏水性,TG酶改性提高了其疏水性,两种处理方法联用降低了SPI的疏水性.两种改性方式均使SPI游离氨基含量减少,但增强SPI的内源性荧光,并提高SPI乳化能力,乳化活力指数由45.82 m2·g-1增大到67.00 m2· g-1.%The soy protein isolate(SPI),transglutaminase(TG) and three monosaccharides were used to simulate the wet-heating Maillard reaction and TG cross-linking in order to modify SPI's properties.The free amino group,solubility and emulsification of SPI were analysed.The results showed that TG could accelerate the Maillard reaction.The degree of glycosylation was:D-galactose＞glucose＞D-fructose.Glycosylation increased the SPI solubility,but TG treatment decreased the solubility,and the combination of two methods had little effect on the solubility.However,TG modification improved hydrophobicity,but glycosylation reduced hydrophobicity,and the combination of the two methods reduced hydrophobicity.Both methods reduced the number of free amino groups,but enhanced the intrinsic fluorescence and improved the emulsifying ability,and the emulsifying activity index increased from 45.82 m2/g to 67.00 m2 · g-1.