Abstract: In this study, the flavor composition of typical base liquors for Maotai-flavor Baijiu from different mechanized brewing rounds was analyzed by liquid-liquid extraction (LLE) combined with gas chromatography-mass spectrometry (GC-MS) based on retention index. The characteristic aroma compounds were determined by their odor activity values, and their relationship with sensory properties was evaluated. The results showed that a total of 37 characteristic aroma compounds were identified. The contribution of each class of volatile compounds to the aroma of typical base liquors from each brewing round was consistent with the sensory evaluation results. The aroma of the base liquors from the first and second rounds was clean with the fruity and fruity notes being superior to the soy?sauce-like note. The base liquors from the third, fourth and fifth rounds had a more prominent soy?sauce-like note, the base liquor from the sixth round had stronger roasted and caramellic notes, and the base liquor from the sixth round exhibited a stronger burnt note together with weakening of other notes. Nineteen compounds including ethyl valerate, ethyl isovalerate, ethyl hexanoate, butyl hexanoate and ethyl octanoate were found to be the main contributors to the fruity, floral and sweet aromas, and the contributors to the roasted and nutty aromas included isobutanol, 2,6-dimethylpyrazine, 2,3,5-trimethylpyrazine and 2-ethyl-6-methyl pyrazine. Furfuryl alcohol and furfural were identified as major caramel-like aroma compounds, and acids as major cheese-like aroma compounds.

Key words: typical base liquor for Maotai-flavor Baijiu; gas chromatography-mass spectrometry; odor activity value; partial least squares regression