Molecular Characterization and Reconstruction of the Umami Taste System in Soy Sauce through a Sensomics Approach

A systematic knowledge of key umami contributors is essential for the targeted quality improvement of fermented soy sauce. In this study, an integrated sensomics strategy combining peptidomics, quantitative analysis, taste reconstitution, and omission/readdition experiments was applied to two fermented soy sauces (AS and FN). Forty-four nonvolatile compounds were incorporated into complete reconstitution models, which closely reproduced the sensory profiles of the authentic samples, with overall similarities of 96.9% for AS and 94.6% for FN. Group omission decreased umami most strongly upon amino acid removal (30.9% in AS and 23.7% in FN), while organic acids, nucleotides, and peptides also contributed to umami, mouthfulness, and overall balance. Further single-compound omission and readdition experiments identified 18 key umami contributors in AS (9 amino acids, 3 organic acids, 2 nucleotides, and 4 peptides) and 21 in FN (11 amino acids, 4 organic acids, 1 nucleotide, and 5 peptides), revealing a hierarchically organized multicomponent umami system.