Reveal the flavor quality changes of soy sauce during shelf life through metabolomics

Soy sauce contains abundant flavor compounds, which are prone to change during storage. This leads to a decline in amino acid nitrogen content, accompanied by undesirable flavor shifts, including increased sourness and bitterness, as well as aroma deterioration. Using three metabolomics approaches, the compounds of 12 kinds of soy sauce were analyzed before and after accelerated shelf life testing (ASLT), identifying a total of 132 volatiles and 44 non-volatiles. Multivariate data analysis (OAV, TAV, OPLS-DA, FC and significance difference) pinpointed 9 key aroma and 15 key taste compounds in the shelf life of soy sauce, which were further verified by constructing a metabolite model and conducting sensory validation experiments. The sensory changes observed in soy sauce shelf life was explained at the metabolite level. This study conducted a comprehensive analysis of soy sauce quality changes during storage, which will be of significant theoretical value for the soy sauce industry development.