Differences in Flavor Profiles of Luzhou-Flavor Base Baijiu from Different Aged Cellars

To investigate the distribution of flavor components in Luzhou-flavor base baijiu from different aged cellars, the aroma components in 18 samples of Luzhou-flavor base baijiu from three cellars of different ages were identified and quantified by direct injection (DI), liquid-liquid extraction (LLE) or vortex-assisted surfactant-enhanced emulsification liquid-liquid microextraction (VSLLME) combined with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The differences in flavor among different base baijiu samples was analyzed by chemometrics methods such as principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and Spearman’s correlation coefficient. The results suggested that 151, 154 and 159 volatile compounds were identified in base baijiu from freshly prepared cellar and those aged over 30 and 100 years. In total, 148 aroma compounds were common to the three base baijiu, accounting for 93.1% of the total number of identified compounds. The quantitative analysis of 61 major aroma compounds showed that the concentrations of ethyl caproate, ethyl butyrate, hexanoic acid, butyric acid and acetic acid in base baijiu from each cellar exceeded 100 mg/L. The concentration of ethyl caproate was the highest, ranging from 1 156.4 to 2 142.2 mg/L. Chemometric results indicated that the flavor similarity of base baijiu between the new and over-30-year-old cellars was higher when compared with the cellar aged over 100 years. This findings further strengthen the baijiu industry’s conventional knowledge of the influence of cellar age on the flavor of Luzhou-flavor baijiu.