Abstract
It is of great significance for the aquaculture industry to determine how rearing salinity impacts fish flesh quality. In the present study, largemouth bass was cultured in different salinities (0%, 0.3%, 0.9%) for 10 weeks, and the effect on flesh texture, flavor compounds, taste, and fatty acid composition was evaluated. We show that rearing salinity not only increased flesh water-holding capacity, but also enhanced muscle hardness, chewiness, gumminess, and adhesiveness, which was consistent with the finding in the shear value test. Morphology analysis further revealed that the effect of salinity on flesh texture was probably related to changes in myofibril diameter and density. As for the taste of the flesh, water salinity improved the contents of both sweet and umami amino acids, and reduced the contents of bitter amino acid. Meanwhile, the content of IMP, the dominant flavor nucleotide in largemouth bass muscle, was significantly higher in the 0.9% group. Interestingly, electronic-tongue analysis demonstrated that the positive effect of salinity on flavor compounds enhanced the umami taste and taste richness of flesh. Moreover, rearing salinity improved the contents of C20: 5n-3 (EPA) and C22: 6n-3 (DHA) in back muscle. Therefore, rearing largemouth bass in adequate salinity may be a practical approach to improving flesh quality.