This study investigated the flavor regulatory mechanism of mixed-strain fermentation in low-salt fish sauce from yellowfin tuna dark meat, based on physicochemical properties, microbial communities, and metabolite profiles. Pediococcus acidilactici and Staphylococcus xylosus at the optimal ratio of 1:2 synergistically increased the amino acid nitrogen content to above 0.7 g/100 mL. Amplicon sequencing revealed distinct microbial communities among the unfermented, single-strain, and co-fermentation groups. Eight core differential genera were identified between co-fermentation and unfermented groups, with Lactiplantibacillus and Pediococcus dominant in the co-fermentation group. Compared with the unfermented group, SPME-GC–MS and LC-MS identified 16 key differential volatile metabolites and 20 downregulated non-volatile metabolites in the co-fermentation group. These metabolites enhanced fruity, fatty, cheesy, and other flavors of fish sauce, and were enriched in ABC transporter, purine/nucleotide metabolism, and other pathways. Overall, co-fermentation provides theoretical and technical support for the process development and flavor regulation of low-salt fish sauce.
You et al. (Mon,) studied this question.