Characterization of volatile profiles of three colored quinoas based on GC-IMS and PCA

Characteristic volatile profiles of quinoas were analyzed by gas chromatography–ion mobility spectrometry (GC-IMS) and principal component analysis (PCA). A total of 28 characteristic volatile compounds were detected in quinoas of WQ (white quinoa), RQ (red quinoa) and BQ (black quinoa), and aldehydes (23.99%～36.81%), alcohols (22.65%～26.50%), ketones (12.30%～19.97%), acids (9.69%～10.10%) and esters (13.30%～30.99%) were common in quinoas. Hexanal (5.47%～16.86%), acroleine (9.13%～12.68%), ethanol (9.17%～11.89%), 2-propanol (4.99%～6.19%), 2-propanone (9.72%～12.96%), propanoic acid (5.56%～6.30%), and propyl butanoate (9.02%～21.14%) were dominant in quinoas, and significant different (p < 0.05) content of these volatile compounds were presented in different quinoas. For the highest content of volatile compounds in different quinoa sample, WQ was characterized by hexanal, pentanal, phenylacetaldehyde, 1-hexanol, 2-pentanol and 1-pentanol, RQ was characterized by 2,3-butanedione, 2-butanone, 2-propanone, butyrolactone, 2-methylpropanol, 2-methylbutanol, acroleine, propanal and butanal, BQ could be characterized by heptanal, 2-propanol, butyl acetate, ethanol, ethyl acetate, butyl propanoate, propyl butanoate and ethyl hexanoate, respectively according to PCA. In conclusion, visual plots of GC-IMS well agreed with PCA, and their combination was excellent for the characterization of aroma profiles of different quinoas.