Characterization of the typical fragrant compounds in traditional Chinese type soy sauce
In this work, a total of 35 important aroma compounds with odor activity values (OAVs) greater than 1 were detected by gas chromatography–mass spectrometry (GC–MS) in traditional Chinese-type soy sauce. Of these, fragrant compounds with aromatic rings (20 compounds) accounted for a large proportion, over 57%. Combining principal component analysis and GC–olfactometry–MS (GC–O–MS), 5-methyl-2-furanmethanethiol (OAV: 284–467), 3-methylbutanal (OAV: 409–938), phenylacetaldehyde (OAV: 47.4–566), 2–phenylethanol (OAV: 7.41–14.3), phenylethyl acetate (OAV: 7.00–18.1) and ethyl phenylacetate (OAV: 12.7–21.3) were confirmed as the typical fragrant compounds among all samples. Furthermore, full two-dimensional gas mass spectrometry (GC × GC–TQMS) was applied and 414 aroma compounds were identified, which included another 85 fragrant compounds with aromatic rings.