Identification of key volatiles responsible for odour quality differences in popped popcorn of selected hybrids

Volatile compounds from six hot-air-popped popcorn hybrids, being also classified into three types, were evaluated by a gas chromatograph equipped with a mass spectrometer (GC/MS). In addition, 68 panelists determined odour quality differences of the popped kernels by an aroma ranking test. Total number of volatiles detected by GC/MS were 195, of which 51 peaks were positively identified, 92 peaks were tentatively identified, and 52 peaks were unidentified. The relationships between quality/quantity of volatiles and sensory results revealed that 2-acetylpyridine was considered to contribute to the overall popped popcorn aroma quality favorably or not adversely. However, 2,5-dimethylpyrazine, (E,E)-2,4-decadienal, 2-methylpyrazine, ethylpyrazine, 2-ethyl-5-methylpyrazine and 3-ethyl-2, 5-dimethylpyrazine were found to be important popcorn volatiles, but to contribute negatively to characteristic popped popcorn odour. Numerous other volatiles such as 2-furfurylthiol (2-furanmethanthiol), pyrrole, 3-(methylthio)propanal (methional), 3-furaldehyde, 4-vinyl-2-methoxyphenol (4-vinylguaiacol), 2-pentylfuran, 2-furanmethanol (furfuryl alcohol), hexanal, 1-pentanol, 2-methyl-5-vinylpyrazine, 2-methoxyphenol (guaiacol), 2-acetylpyrrole and others may be responsible in part of typical popcorn aroma characteristics.