Dual enhancement effects of different yeast extract on gel properties and saltiness perception of low-salt surimi gel from silver carp

This study investigated the dual enhancement effect of five yeast extracts (YE) on gel properties and saltiness perception of low-salt (1% NaCl) surimi gels. The addition of YE not only pronouncedly enhanced the gel strength, texture properties (hardness, cohesiveness and chewiness) and elasticity of low-salt surimi gel (P < 0.05), but also increased the gelation rate of surimi during kamaboko stage. When YE was added, the water holding capacity of surimi gels increased, accompanied by decreased water fluidity, and composite gels exhibited a relatively dense and ordered microstructure. Electronic tongue analysis indicated that YE addition enhanced umami and saltiness, and decreased the sour and bitterness characteristic values (P < 0.05). Besides, sensory evaluation showed that YE increased the texture, saltiness, umami and smell score of low-salt surimi gel (P < 0.05), and the saltiness perception of low-salt surimi gel added with YE1 and YE2 was similar to normal-salt surimi gel (2% NaCl), which was consistent with the result of electronic tongue. The correlation analysis result revealed that the enhancement of gel properties of surimi may be attributed to the charged amino acids (Arg, Lys, His, Glu and Asp) in YE, and the umami substances (Glu, Asp, IMP and GMP) in YE could not only improve the umami taste, but also enhance the saltiness perception of low-salt surimi gel. Overall, YE had the dual effect of remarkably improving the gel properties and enhancing saltiness perception of low-salt surimi gel, providing a salt reduction effect, with YE2 being the best.