Study of Shanxi aged vinegar by non-targeted metabolomics techniques and antioxidant activity characteristics

The quality and flavor of Shanxi Aged Vinegar (SAV) are closely related to its aging time. In this study, for the first time, UPLC-Q-TOF/MS combined with non-targeted metabolomics techniques were employed to analyze SAV samples from 5 different years. The antioxidant activities were evaluated using ABTS and DPPH assays. The non-targeted metabolomics results identified a total of 99 metabolites, among which 24 were significantly associated with the aging time of SAV and were identified as potential markers of vintage, including key components such as organic acids, amino acids, and polyphenols. They contribute significantly to the unique flavor and nutritional value of SAV. Specifically, in SAV aged for 10 years, the contents of citric acid, L-malic acid, L-glutamic acid, protocatechuic acid, and hydroferulic acid were significantly higher than in other vintages. The results of ABTS and DPPH antioxidant activities indicated a positive correlation between the antioxidant activity of SAV and its aging time. Among the 12 identified polyphenols, chlorogenic acid may be the primary contributor to the antioxidant results of SAV. This study provides important references for further exploration of the health value and antioxidant mechanisms of SAV.