Revealing the key flavor components of Pixian Doubanjiang by molecular sensory science and flavor omics approaches and the interactions among flavor substances by quantum chemistry calculation.

The identification of characteristic volatile compounds in Doubanjiang is of great significance for aroma analysis. In this study, the flavor components of Pixian Doubanjiang at different stages were systematically detected by using flavoromics techniques and quantum mechanics. The results suggested that electronic nose combined with OPLS-DA model effectively distinguished the samples with different fermentation stages. Linalool, phenylacetaldehyde, ethyl phenylacetate, ethyl decanoate, phenethyl ethanol and methyl linoleate were identified as the key aroma components based on OAV analysis, with ethyl phenylacetate being considered as the core aroma component. Then, density functional theory (DFT) was employed for the first time to explore the interactions among Doubanjiang flavor substances at the molecular level, which indicated that ethyl phenylacetate interacted with other flavor substances through electrostatic adsorption to achieve a steady state. These results elucidated core aroma components and molecular binding mechanisms governing Doubanjiang flavor, revealing DFT as a predictive framework for flavor modulation.