Investigating the temporal evolution of physicochemical attributes and flavorome profiles in Sichuan shai vinegar utilizing diverse aging techniques

Sichuan shai vinegar (SSV) is an acidic condiment with a long history and unique flavor. Aging is an important production process that determines the unique flavor of shai vinegar. This study compared the differences in physicochemical properties, volatile flavor, and non-volatile flavor substances between the constant temperature aging and natural aging methods of SSV Cupei . The results showed that the total acid and amino acid nitrogen content in naturally aged vinegar was higher than that in constant temperature aged vinegar. Furthermore, 20 different volatile flavor substances and 65 different non-volatile flavor substances were obtained after 21 and 25 days of constant temperature aging and 1, 3, and 5 years of natural aging SSV samples. This indicates that the temperature environment during natural aging was more moderate, allowing acidic compounds to form and stably exist in the aging environment. Correlation analysis further demonstrated that there were more differentiated non-volatile substances significantly related to the Maillard reaction under constant temperature aging condition and related to antioxidant activity under natural aging condition. The results of this study provide a comprehensive understanding of the characteristics and applications of the two aging methods of SSV and guide strategy for factories in the selection of aging methods.