Characterization of the key aroma-active compounds in Yangjiang Douchi by sensory-directed flavor analysis

As a kind of traditional fermented soybean food in China, douchi produced in Yangjiang is widely used in Cantonese cuisine and prepared foods and is exported to more than 30 countries. Yangjiang Douchi has a unique flavor and in-depth research on it can enhance its aroma quality. In this study, the key aroma-active compounds were characterized by the combined gas chromatography–olfactometry detection (GC–O) and gas chromatography–mass spectrometry (GC–MS) with sensory evaluation. In total, 39 aroma compounds were identified, and 18 of them with flavor dilution (FD) > 4 were determined. After quantifying, it was found that there were 12 aroma-active compounds with odor activity value (OAV) > 1. It was further verified that 9 aroma-active compounds contributed greatly to the aroma including acetic acid, 4,5-dimethyl-3-hydroxy-2,5-dihydrofuran-2-one, 3-methylbutyric acid, maltol, guaiacol, phenylacetaldehyde, furanone, 3-methylthiopropanal and 1-methoxy-4-propenylbenzene. Sensory evaluations showed that the flavor profile mainly consisted of sauce-like, sour, nutty, smoky, caramel-like, and fruity notes.