Preparation of no-salt-added fish sauce with aroma and umami coexistence from yellowfin tuna dark meat

Fish sauce is a popular aquatic condiment with a unique flavor. This study aims to efficiently prepare a no-salt-added fish sauce from yellowfin tuna dark meat and characterize its flavor profiles. The enzymatic hydrolysis and fermentation conditions in preparing fish sauce were optimized first based on single-factor and response surface experiments. The fish sauce obtained had an amino acid nitrogen content of 0.603 g/100 mL and a salt content of 0.128%, and showed favorable improvement in appearance, odor, and taste. HS-GC-IMS analysis revealed that more esters with pleasant aromas and fewer aldehydes with fishy odors were produced during fish sauce processing. Furthermore, two potential umami peptides were identified from fish sauce through LC-MS/MS and virtual screening, both of which were embedded within the T1R1 subunit via hydrogen bonding. These results provide a theoretical basis for the efficient production of no-salt-added fish sauce and high-value utilization of yellowfin tuna dark meat.