Effect of soy protein isolate, egg white protein and whey protein isolate on the flavor characteristics of silver carp (Hypophthalmichthys molitrix) surimi

The objective of this study was to investigate effects of soy protein isolate (SPI), egg white protein (EW) and whey protein isolate (WPI) on flavor characteristics of silver carp surimi. A total 72 volatile odor compounds (VOCs) were identified in surimi gels with non-muscle proteins (NMPs). SPI had significant effects on the VOCs with low thresholds in surimi gels, while EW had relatively lower effect. They all reduced undesirable VOCs, such as nonanal, 1-octen-3-ol. Three proteins reduced fatty acids (FAs) in surimi, while most free amino acids (FAAs) were reduced in surimi with SPI or EW. Most of the VOCs had higher positive correlation with FAAs in surimi with SPI or WPI, but negative correlation with EW. FAs of surimi with SPI were higher than those with EW or WPI, while a few of VOCs (1-octen-3-ol, hexanal and nonanal) had higher correlation with FAs. Three proteins reduced protein and lipid oxidations in surimi gels, while WPI more reduced protein and lipid oxidations. FAAs were main causes of VOC changes in surimi gels with NMPs. Results suggested NMPs could modify the flavor of surimi gels and cover up the fishy odor and 2% or 4% was the appropriate addition of NMPs.