WEN He, ZHA Shuanglong, HU Xiangfei, ZHANG Panwen, YANG Huilin, WANG Xiaolan
Aspergillus-type Douchi is a traditional Chinese fermented food. In order to explore the changes of volatile components in the rapid fermentation process of Aspergillus-type Douchi, gas chromatography-mass spectrometry coupled with solid phase micro-extraction (SPME-GC-MS) was used to detect the volatile components in cooking, making, washing and post-fermentation. The volatile components in the production process included nine kinds of compounds, i.e. esters, ketones, phenols, alcohols, aldehydes, acids, pyrazines, furans and aromatics groups. Sixty-seven volatile components were detected in the cooking stage, mainly including alcohols, phenols and aldehydes. The highest volatile components were 1-octene-3-ol, n-hexanol and maltol, among which 1-octene-3-ol was the main source of bean odor. Seventy volatile components were detected in the making stage, mainly including alcohols, aromatic groups, acids and furans. The higher volatile components were 1-octene-3-alcohol, styrene, 2-n-pentylfuran, while mild Maillard reaction occurred. Sixty-seven volatile components were detected in the washing stage, mainly including acids, alcohols, aromatics and furans. A large number of 1-octene-3-ol were washed away. Eight-one volatile components were detected in the post-fermentation stage, mainly including aldehydes, acids, phenols and pyrazines. At this stage, the Maillard reaction was intense, large amount of benzaldehyde, cocal, guaiacol, 2, 5-dimethylpyrazines, 2-methylpyrazines and other volatile components were produced. In the production process of Aspergillus-type Douchi with rapid fermentation, the production of volatile components was limited in the making stage, and the post-fermentation stage was the main stage of the formation of volatile flavor substances in Aspergillus-type Douchi.
