Exploring Changes in Key Aroma-Active Compounds of Soy Sauce Due to Different Fermentation Processes

In this study, two extraction methods combined with gas chromatography-olfactometry-mass spectrometry (GC×GC-O-MS) were used to investigate the sensory characteristics of high-salt dilute fermented soy sauce (HDFSS), and molecular sensory methods were used to characterize its aroma. A total of 81 aroma-active components were identified and analyzed in HDFSS. Among them, 3-methylthiopropanal had the highest odor activity value (OAV) in HDFSS, and acetic acid had the highest content in HDFSS. The results showed that the concentrations of benzyl alcohol, phenethyl alcohol, 1-octen-3-ol, maltol, and 1-hydroxy-2-propanone did not vary significantly in the HDFSS of different fermentation processes. The Y2 HDFSS produced in fermenter No. 2 had higher concentrations of 3-methyl-1-butanol (malt flavor) and 3-methylthiopropionaldehyde (baked potato aroma), and also received the high aroma scores in the sensory evaluation. Finally, by conducting aroma reconstitution and omission experiments on HDFSS from two different fermentation processes, the key aroma-active compounds, such as phenethyl alcohol, maltol, and guaiacol, were identified.