Insights into Aroma Evolution in Strong-Flavor Baijiu during Aging Based on E-Nose, E-Tongue, and HS-SPME-GC-MS

The aging stage is often accompanied by intricate physicochemical reactions and aroma interactions, which play a crucial role in shaping the flavor profile and overall quality of strong-flavor Baijiu (SFB). This study employed E-nose, E-tongue, and HS-SPME-GC-MS technologies, combined with multivariate statistical analysis, to conduct a comparative analysis of flavor evolution in eight SFB samples aged for 0, 1, 2, 4, 6, 8, 10, and 15 years, respectively. The results demonstrated that, with an increase in aging, the total acid and total ester levels showed a trend of increasing acid and decreasing ester. E-nose and E-tongue showed strong potential in identifying aged SFB. A total of 86 volatile compounds were determined by GC-MS, predominantly comprising esters, acids, and alcohols. Orthogonal partial least squares discriminant analysis (OPLS-DA) demonstrated that significant characteristic flavor compounds in aged SFB include ethyl caproate, ethyl acetate, hexanoic acid, acetaldehyde, ethyl lactate, 1-hexanol, acetic acid, 3-methyl-1-butanol, ethyl butyrate, 1-octanol, 1-propanol, butyric acid, ethyl caprylate, 1-butanol, and 2-methyl-1-butanol. By investigating the flavor evolution dynamics of different-aged SFB during the aging process, a theoretical basis for the flavor formation mechanism of SFB is provided, and application cases are offered for improving the quality control of Baijiu production.