Insights into the Role of Glycerol as a Marker for Differentiation of Different Flavor Types of Baijiu

Glycerol has essential effects on the flavor of alcoholic beverages. However, the non-volatility and low contents of glycerol and the presence of high ethanol content make it difficult to detect in Baijiu. In this study, a derivatization method combined with gas chromatography–mass spectrometry was used to characterize and quantify glycerol in 12 main flavor types of Baijiu for the first time. The average contents of the glycerol in Soysauce (8.36 ± 2.78 mg/L), Sesame (15.96 ± 0.83 mg/L), and Feng (12.69 ± 2.38 mg/L) flavor types were higher than those in other types. One-way analysis of variance was used to analyze the differences of glycerol in different types of Baijiu among the selected variants, i.e., fermentation process, starter, fermentation container, and raw material. The results showed that there were significant effects of these selected categories on the glycerol in Baijiu. The results of heatmap and hierarchical cluster analysis, further indicated that the production temperature of the fermentation starter may be the key factor affecting the contents of glycerol in Baijiu.