Characterization of the key aroma compounds in mulberry fruits by application of gas chromatography-olfactometry (GC-O), odor activity value (OAV), gas chromatography-mass spectrometry (GC-MS) and flame photometric detection (FPD)

The volatile compounds of mulberries obtained from three cultivars (M. nigra, Y1, M. Macroura, Y2 and M. Alba, Y3) were investigated by gas chromatography-olfactometry (GC-O), odor activity value (OAV), gas chromatography-mass spectrometry (GC-MS) and flame photometric detection (FPD). The results showed that 41, 37 and 41 compounds were detected in Y1, Y2 and Y3 samples, respectively. In addition, 12, 11, and 12 sulfur compounds were identified in three samples by FPD, respectively. Quantitative analysis showed 2-(methylthio)ethanol, methionol, dimethyl sulfide, methional and 3-ethylthiophene were present in relatively high amounts in each of the three samples. Furthermore, benzaldehyde, ethyl butanoate, (E)-2-nonenal, 1-hexanol, hexanal, methional, 3-mercaptohexyl acetate and 3-mercaptohexanol were present with much higher OAVs than other compounds. Finally, four compounds (pentanal, ethyl acetate, acetic acid, methionol) were selected to investigate possible effects on six descriptors, which indicated that the volatile compounds at sub-threshold concentrations are likely to contribute to overall aroma.