Abstract: 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.

Key words: myofibrillar protein; external proteins; fishy-odor compounds; binding capacity; protein structure