Study on volatile substances during the reddening process of soybean

To find the characteristic volatile substances of reddening, in this study, the change of volatile substances in the process of soybean reddening was investigated. The volatiles of two varieties of soybeans, Zhonghuang 35 and Zhonghuang 37, were detected and analyzed in the early, middle and late stages of the reddening process by headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that hydrocarbons, aldehydes, ketones, esters, aromatics, and furans volatile substances increased significantly during the soybean reddening process. The hydrocarbons were the most significantly increased substances among all these kinds of substances. The hydrocarbons substances, d-limonene, dodecane, undecane, decane, 2-methyldecane, 3-methyldecane, 3-methyundecane, 2,6-dimethyldecane; the ketone substance, 3-octanone; and the ester substances, gamma-nonanolactone and gamma-pentanolactone could not be detected in the normal soybeans, while they were detected in all the reddening soybean samples. D-limonene and 3-octanone varied significantly and could be served as characteristic volatiles of soybean reddening.