Abstract: In order to fully understand the change of flavor compounds during the fermentation of mechanically produced Shaoxing rice wine, samples were taken throughout the fermentation process for measurement of organic acids, polyphenols, amino acids and volatile components by high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Principal component analysis (PCA) was used to discriminate among the samples from different stage of fermentation based on their characteristic flavor profilesss. The results showed that concentrations of organic acids, amino acids and higher alcohols increased rapidly in the first 48 hours, volatile phenols in the first 72 hours and esters in the first 120 hours, which indicated that the flavor components were mainly produced in the early fermentation stage. Bitter amino acids dominated the amino acid composition in all samples. The phenol composition was dominated by catechin in the early fermentation stage but epicatechin in late fermentation stage. PCA results demonstrated that the cumulative contribution rate of the first PCs to the total variance was 60.52% and that PC1 could clearly distinguish between the samples from the early and late stages. In addition, nonvolatile components could well explain the samples from different stage of fermentation.

Key words: mechanically produced rice wine, volatile flavor components, non-volatile flavor components, dynamic monitoring