Elevated levels of branched chain fatty acids in low‐salt fish sauce by co‐fermentation: flavor improvement and metabolism analysis

Abstract BACKGROUND Traditional fish sauce products rely on relatively long fermentation time and high salt concentration, resulting in inconsistent quality and health risks. Branched‐chain fatty acids (BCFAs) are associated with nutritional benefits and health‐care effects, mainly derived from food fermentation. This study aimed to screen BCFAs‐producing bacteria with high protease and aminotransferase activity as starter cultures for fish sauce fermentation. RESULTS The low‐salt fish sauce products were obtained by co‐fermentation with three chosen strains. Trichloroacetic acid (TCA)‐soluble peptides and amino acid nitrogen concentrations were higher in the co‐fermentation group (FH group). The organoleptic evaluation showed co‐fermentation optimized flavor composition and endured with rich taste. The levels of BCFAs and branched‐chain amino acids (BCAAs) significantly increased by co‐fermentation. Volatile metabolomics analysis indicated that BCFAs, branched‐chain esters, and pyrazines were the key flavor compounds in the co‐fermented group. CONCLUSION The co‐fermentation system with selected strains to ferment low‐salt fish sauce has the potential to increase BCFA content and improve flavor and nutrition. © 2024 Society of Chemical Industry.