Analysis of the relationship between microorganisms and flavour development in dry-cured grass carp by high-throughput sequencing, volatile flavour analysis and metabolomics

Complex microbial community plays an important role for flavor formation in traditional dry-cured grass carp. To investigate the correlation between microorganisms and flavour development, the bacterial diversity and flavour quality of dry-cured fish at different stages of fermentation were analysed using high-throughput sequencing, volatile flavour analysis and metabolomics. Cobetia, Staphylococcus and Ralstonia were the dominant genera in dry-cured fish, with relative abundances of 37.78%, 34.46% and 3.2%, respectively. The flavour of dry-cured fish samples varied as the abundance of aldehydes, alcohols, small peptides, FAAs and carboxylic acids showed a great increase during fermentation. Moreover, there were significant correlations (P < 0.05) between specific microorganisms and volatile indicators, as well as flavour metabolites. Staphylococcus, as the dominant bacterial genus, is involved in the mechanism of flavour formation in dry-cured fish during fermentation. This information is useful for elucidating the mechanism of flavour formation in dry-cured fish.