Abstract: An electronic nose and gas chromatography-mass spectrometry (GC-MS) were used to analyze the volatile flavor components of kvass made in our laboratory and four commercial brands of kvass, Ochakovskiy, Pabaebckhh, Qiulin and Wahaha. The obtained data were analyzed by principal component analysis (PCA). The results showed that the electronic nose could clearly distinguish among the flavors of the five kvasses. The flavor of laboratory made kvass was close to that of Pabaebckhh and Ochakovskiy kvass, but was greatly different from that of Qiulin and Wahaha kvass. This difference may be caused by the use of different fermentation starters. GC-MS analysis demonstrated that the flavor difference could be caused by differences in the contents of volatile flavor compounds such as ethanol, sorbic acid, phenylacetaldehyde, phenylethyl acetate and benzaldehyde.

Key words: kvass, volatile flavor components, principal component analysis, electronic nose, gas chromatography-mass spectrometry