糖基化大豆分离蛋白对肌原纤维蛋白功能特性的影响

摘要

Glycosylated soybean protein isolate (SPI) was prepared by reaction between SPI and glucose at a ratio of 1∶1 (m/m) at 70 ℃ for 4 h,and its blends with myofibrillar protein (MP) at different ratios of 9∶1,8∶2,7∶3,6∶4 and 5∶5 (m/m) were determined for emulsifying properties,turbidity,surface hydrophobicity and gel properties (texture properties,whiteness and microstructure) in order to elucidate the effect and mechanism of glycosylated SPI on the functional properties of MP.The results showed that the emulsifying properties and surface hydrophobicity of glycosylated SPI and MP blends were significantly improved compared with MP (P ＜ 0.05).The turbidity of the blended proteins rose with increasing temperature (30-80 ℃),but it decreased with higher proportion of glycosylated SPI.The gel hardness and springiness of MP and glycosylated SPI blends were significantly better than those of MP and native SPI blends (P ＜ 0.05),and the gel microstructure was more compact and uniform than that of MP and native SPI blends.Compared with MP,the gel whiteness of the mixed proteins significantly decreased,except for no significant difference at a mixing ratio of 9∶1 (P ＞ 0.05).%选择70℃条件下反应4h所得到的糖基化大豆分离蛋白样品(蛋白与葡萄糖质量比1∶1)与肌原纤维蛋白以不同比例(9∶1、8∶2、7∶3、6∶4、5∶5)进行复配,测定不同复合蛋白的乳化性能、浊度、表面疏水性、凝胶特性(质构特性、白度值、微观结构分析),探讨糖基化大豆分离蛋白对肌原纤维蛋白功能性质的影响及其机理.结果表明:复合蛋白的乳化性和表面疏水性均较肌原纤维蛋白显著提升(P＜0.05);复合蛋白的浊度随着加热温度的升高(30～80℃)而不断增加,随着糖基化大豆分离蛋白比例的加大,浊度不断变小;肌原纤维蛋白与糖基化大豆分离蛋白混合凝胶的硬度和弹性均显著优于其与天然大豆分离蛋白混合凝胶(P＜0.05),微观结构比其与天然大豆分离蛋白混合凝胶更加致密均匀;与纯肌原纤维蛋白凝胶相比,混合凝胶的白度值下降,但混合比例为9∶1时白度值下降不显著(P＞0.05).