Abstract: The key flavor compounds of Xiaoqu mild-flavor baijiu were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The differences in key flavor compounds between two quality grades of Xiaoqu mild-flavor baijiu were analyzed by multivariate statistics. The results showed that the two quality grades of Xiaoqu mild-flavor baijiu were similar in terms of volatile aroma composition. The contribution of ethyl esters to the flavor of the superior grade was greater than to that of the first grade, while the opposite was observed for some higher alcohols, sulfides, aldehydes and ketones. Partial least squares-discriminant analysis showed that significant differences in the contents of ethyl acetate, ethyl lactate, isobutanol, isoamylol and acetaldehyde existed between the two quality grades of Xiaoqu mild-flavor baijiu, which might be the key factor causing the differences in sensory evaluation and flavor characteristics between them.

Key words: Xiaoqu mild-flavor baijiu; analysis of key flavor components; gas chromatography-mass spectrometry- olfactometry; headspace solid phase microextraction-gas chromatography-mass spectrometry; sensory evaluation