Succession patterns of aroma components during brewing process of broomcorn millet (Panicum miliaceum L.) Huangjiu.

The flavor of Huangjiu is closely related to its brewing technology. Patterns of aroma component succession during the process of brewing broomcorn millet Huangjiu were investigated by solvent-assisted flavor evaporation combined with gas chromatography-mass spectrometry and chemometrics. During fermentation, esters, alcohols, acids, ketones, acetals, sulfur compounds, furans, and lactones were formed mostly in the chief fermentation stage; nitrogenous and phenolic compounds increased in the primary fermentation stage and then decreased; aldehydes decreased after fermentation started; and terpenes decreased after five days. During aging, acids, alcohols, ketones, lactones, phenols, and nitrogenous and sulfur compounds first decreased and then increased; and esters, acetals, aldehydes, and furans always increased, while terpenes decreased continuously. Key odorants, including acetic acid, 3-methylbutanoic acid, 1,1-diethoxyethane, and 3-methylbutanal, were produced in large quantities in the primary fermentation stage; ethyl lactate, β-phenylethanol, and 2/3-methyl-1-butanol were generated in large quantities in the chief fermentation stage; and sotolon and methional were generated in the aging stage. This study is of great significance for the quality control of Huangjiu production.