Volatile Components in Three Commercial Douchies, A Chinese Traditional Salt-Fermented Soybean Food

Douchi is a traditional fermented soybean product originated in China and it has been consumed since ancient times as seasoning for food. Volatile components of three commercial douchies were extracted using a simultaneous steam distillation and extraction apparatus (SDE). The extracts were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 131 compounds were identified, but only 25 components were common to all three brands. Major classes of compounds included esters (29), acids (18), alcohols (16), pyrazines (14), ketones (13), aldehydes (12), phenols (6), hydrocarbons (5), furans (5), sulphur-containing compounds (5), pyridines (4), pyrimidines (2), and miscellaneous compounds (2).