Volatile components in fermented soybean (Glycine max) curds.

Volatile components of three commercial fermented soybean (Glycine max) curds (FSC) (A-C) were extracted using a simultaneous steam distillation and extraction apparatus, and extracts were analyzed by gas chromatography/mass spectrometry. A total of 111 compounds was found. Sixty-three compounds were common to all three brands. Brands A, B, and C contained 90, 90, and 82 components, respectively. Major classes of compounds included alcohols (32) and esters (25). Similarities and differences existed in the composition of the FSC samples. Twelve common compounds including six esters, four alcohols, one ketone, and one miscellaneous compound had a dry weight of >1000 microg/kg of sample. Quantitative differences existed among the commercial brands (p<0.05). The quantity of ethanol detected might produce large numbers of ethyl esters that contribute to the desirable fruity and floral notes for the final products.