Comparison of two types of vinegar with different aging times by NMR-based metabolomic approach.

Shanxi vinegar (SV) is well known as the most famous vinegar for its distinctive processing technique in China. Aging is the most important process for SV, and we call the vinegar aging more than 1-year Shanxi aged vinegar (SAV) and less than 1-year Shanxi mature vinegar (SMV). In this study, the chemical compositions and in vivo difference between SAV and SMV were compared by NMR based metabolomic profiling technique and multivariate statistical analysis. The results indicated that most of the metabolites exhibited higher concentrations in SAV than those in SMV¸ and the amino acids showed higher concentration ratio than the other compounds. The changes of endogenous metabolites after treatment with SMV and SAV were also investigated. Compared with the chemical differences, the differences of metabolomic changes between SAV and SMV were relatively minor. This study provides a valuable approach for accurately evaluating the differences of food products. PRACTICAL APPLICATIONS: Vinegar is commonly consumed as the important seasoning. SV, which is made from several kinds of cereal by solid-state fermentation techniques, is one of the famous vinegars in China. Aging is the most important process for SV which dividing vinegar into SAV and SMV according to the aging time. Due to the long aging process, the price of SAV is much higher than that of SMV in the market place. However, no investigation was conducted to compare their differences in vivo.