Characterization of key aroma compounds in traditional Chinese soy sauce through the molecular sensory science technique

Sensory evaluation revealed that traditional high-salt liquid-state soy sauce (THLS), a popular seasoning in China, has a caramel-like/sweet, roasted, nutty, cooked potato-like, and spicy/burnt aroma. As a comparative sample, commercial high-salt liquid-state soy sauce (CHLS) showed a similar aroma profile; however, the aroma intensity was stronger and richer in THLS. Gas chromatography - olfactometry - mass spectrometry and aroma extract dilution analysis of the aroma concentrates, prepared by solvent-assisted flavor evaporation, revealed the presence of over 70 odor-active compounds. Among them, methional had the highest flavor dilution factor. Maltol, 4-ethylguaiacol, and phenylacetaldehyde were detected with a higher flavor dilution factor in THLS than in CHLS. Quantitative analysis indicated that the concentrations of 11 key aroma compounds were higher in THLS than in CHLS. The sensory evaluation suggested that the aroma profile of the aroma recombination sample was similar to that of THLS. HEMF, 2-acetyl-1-pyrroline, methional, HDMF, 4-ethylguaiacol, phenylacetaldehyde, 2,3-diethylpyrazine, 2-phenylethanol, furfuryl alcohol, 2,3-butanediol, and maltol imparted the overall aroma profile to THLS.