Characterization of the Major Odor-Active Compounds in Dry Jujube Cultivars by Application of Gas Chromatography–Olfactometry and Odor Activity Value

The volatile compounds of jujube (Ziziphus jujube Mill.) puree obtained from three cultivars, 'Jinsixiaozao' (Y1), 'Youzao' (Y2), and 'Yuzao' (Y3), were analyzed by gas chromatography–olfactometry (GC–O), gas chromatography–mass spectrometry, gas chromatography–flame photometric detection, and a nitrogen phosphorus detector. The results showed that a total of 37, 37, and 35 odor-active compounds were identified by GC–O in samples of Y1, Y2, and Y3, respectively. In addition, the odor activity value (OAV) was used to determine the important compounds. The results demonstrated that hexanal (OAV of 39–85), (E)-2-octenal (OAV of 32–70), β-damascenone (OAV of 14–49), ethyl hexanoate (OAV of 22–39), 3-mercaptohexyl acetate (OAV of 17–24), and 2,5-dimethylpyrazine (OAV of 17–22) were key odor-active compounds. It is of great significance to develop high-grade jujube food by determining key odor-active compounds. Furthermore, four volatiles (hexanal, 1-octen-3-ol, 3-mercapohexyl acetate, and benzaldehyde) reduced the overall threshold value by 2.36, 1.01, 1.34, and 1.19, respectively.