Synthetic microbial communities: A new strategy to enhance texture, taste, and flavor attributes of slightly fermented dried bonito.

This study investigated the effects of the inoculation of synthetic microbial communities (SynComs), including Staphylococcus carnosus, Lactiplantibacillus plantarum, Bacillus coagulans, and Kluyveromyces marxianus, on the safety, texture, taste, and flavor profiles of slightly fermented dried bonito. The results showed that all slightly fermented samples contained very low levels of total volatile base nitrogen and histamine, the fish proteins underwent acid denaturation and coagulation after fermentation, forming a dense and stable three-dimensional network structure that contributed to the appearance of the final products. A synergistic effect among S. carnosus, L. plantarum, and K. marxianus not only reduced the bitterness scores of the e-tongue, but also enhanced the umami and sweetness taste of dried bonito products by increasing the contents of pleasant tasting amino acids, with the equivalent umami concentration 1.89 times (p < 0.05) higher than control group. In addition, a linear relationship was observed between the amount of flavor compounds produced by lipid oxidation and free fatty acids. The co-inoculation of S. carnosus, L. plantarum, and B. coagulans yielded richer flavor compounds in dried bonito, the upregulation of benzaldehyde, 2, 3-dimethyl-2-cyclopentene-1-one, 1-octen-3-ol and heterocyclic compounds led to the development of intense fruity, sweet, mushroom-like and floral aromas. These findings establish a foundation for the selection of composite fermentation starter cultures, enabling the targeted formulation of SynComs with flavor enhancement and texture improvement functions.