Characteristic odor of foxtail millet from different area with different sowing time based on gas chromatography-mass spectrometry

The odor of the foxtail millet is one of the most important indexes to evaluate the foxtail millet quality. Different sowing time results in different quality of the foxtail millet, and the volatiles can be used as fingerprint for distinguish them. The odor components of foxtail millets from spring sowing area and summer sowing area were investigated by means of gas chromatography-mass spectrometry (GC-MS) combined with simultaneous distillation extraction (SDE). A total of 53 volatile compounds were identified in all the samples containing 19 aldehydes, 4 alcohols, 7 ketones, 7 benzene derivatives, 12 hydrocarbons, 3 heterocycles and 1 acid. Aldehydes were the predominant odor components in foxtail millet. Compared with summer sowing area, there were abundant variety and high content of odor components in spring sowing area. Twenty-one volatiles were found to be odor-active compounds. The components with the highest OAVs in most sowing area were (E,E)-2,4-decadienal, (E)-2-nonenal, (E,E)-2,4-nonadienal and nonanal. Finally, 20 volatiles were screened out to distinguish the foxtail millet from spring-sowing area and summer-sowing area by multivariate statistical analysis. The results will be helpful to identify the foxtail millet from different sowing seasons and provide evidence that the spring-sowing foxtail millet shows more active odors.