Analysis of differential components in sauce-flavor Baijiu with different aging years based on non-targeted metabolomics

The substance composition of sauce-flavor (Jiangxiangxing) Baijiu samples (numbered as 5y, 10y, 20y, 35y and 60y) with different aging years (5 year, 10 year, 20 year, 35 year and 60 year) were analyzed through non-targeted metabolomics, and the different substances of sauce-flavor Baijiu with different aging years were explored by principal component analysis (PCA) combined with orthogonal partial least squares-discriminant analysis (OPLS-DA) multivariate statistical analysis. The results showed that a total of 89 volatile compounds were detected from sauce-flavor Baijiu with different aging years by headspace solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS), mainly ethyl palmitate, ethyl hexanoate, and ethyl phenylacetate, and the longer the aging year, the more volatile compounds. There were 17, 21, 17 and 17 main differential volatile compounds among samples of 5y and 10y, 10y and 20y, 20y and 35y, 35y and 60y, respectively. A total of 1 292 non-volatile compounds in sauce-flavor Baijiu with different aging years were detected by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC- MS/MS), and there were 28, 24, 13 and 21 main differential non-volatile compounds among samples of 5y and 10y, 10y and 20y, 20y and 35y, 35y and 60y, respectively, mainly amino acids, fatty acids, organic acids, and aromatic compounds, such as heptanedioic acid, azelaic acid, mannitol, conjugated linoleic acid and so on. These findings revealed the changing law of the composition of sauce-flavor Baijiu with different aging years, and provided a scientific basis for seeking a reasonable aging time of sauce-flavor Baijiu.