外源蛋白对白鲢鱼糜肌原纤维蛋白结构及其结合特征腥味物质能力的影响

Effects of External Proteins on the Structure of Silver Carp Surimi Myofibrillar Protein and Its Capacity to Bind to Characteristic Fishy-Odor Compounds

研究不同添加量(2%、4%、6%)大豆分离蛋白(soy protein isolate,SPI)、蛋清蛋白(egg white protein,EWP)、乳清分离蛋白(whey protein isolate,WPI)对白鲢鱼糜肌原纤维蛋白(myofibrillar protein,MP)结构及其结合特征腥味物质(己醛、壬醛、1-辛烯-3-醇)能力的影响。结果表明,适量外源蛋白可促进MP展开,MP的表面疏水性、浊度、粒径、Zeta电位也随之增加,此时暴露出的疏水基团可增强MP结合己醛、壬醛的能力,暴露出的羟基则可增强MP对1-辛烯-3-醇的结合。外源蛋白添加量进一步增加,添加EWP、WPI的MP结合1-辛烯-3-醇的能力由于蛋白表面增加的亲水基团进一步增强。此外,添加WPI能更好地增强MP结合3种腥味物质的能力。

In this work,the effects of addition of different amounts(2%,4%and 6%)of soy protein isolate(SPI),egg white protein(EWP)and whey protein isolate(WPI)on the structure of silver carp surimi myofibrillar protein(MP)and its ability to bind to fishy-odor compounds(hexanal,nonanal,and 1-octen-3-ol)were investigated.The results indicated that adding an appropriate amount of external proteins could promote the unfolding of MP,thus increasing its surface hydrophobicity,turbidity,particle size,and zeta-potential.Moreover,the exposed hydrophobic group enhanced the ability of MP to bind to hexanal and nonanal,and the exposed hydroxyl group enhanced the ability of MP to bind to 1-octen-3-ol.With increasing amount of added EWP and WPI,the capacity of MP to bind to 1-octen-3-ol increased due to the increased hydrophilic groups on the protein surface.In addition,addition of WPI could better enhance the capacity of MP to bind to the three fishy-odor compounds.