Abstract: In order to clarify the important aroma substances of Pixian bean paste, different extraction methods were applied to extract the aroma substances in Pixian bean paste, and ether was selected as the optimal extraction solvent. The ether extract was fractionated into an acid-water soluble component and a neutral-alkaline component for analysis by gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). A total of 46 aroma substances were identified in Pixian bean paste, including 5 alcohols, 13 volatile organic acids, 7 aldehydes and ketones, 11 phenols, 5 aromatics, 3 heterocyclics, and 2 pyrazines. Six aroma compounds including 3,4-dimethyl-2,5-furandione, crotonicacid, 2,6-dimethoxyphenol, 3-methyl-1,2-cyclopentanedione, γ-butyrolactoneand 3,4-dimethylbenzaldehyde were first identified in Pixian bean paste. Acetic acid, 3-methylbutyric acid, 3-methylvaleric acid, 2-phenylethanol, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (HDMF), phenol, 1-octen-3-one, 3-methylthiopropionaldehyde and eugenol were identified as important aroma substances of Pixian bean paste.

Key words: Pixian bean paste; gas chromatography-olfactometry; gas chromatography-mass spectrometry; aroma substances; 2,6-dimethoxyphenol; 3,4-dimethyl-2,5-furandione