Flavor characterization and perceptual interactions of key aroma compounds in Zhoushan fish sauce: A combined approach of GC-MS, GC-E-Nose, Feller's additive model, σ-τ plot and molecular docking

Eight key odorants identified in Zhoushan fish sauce via GC-MS, GC-E-nose, OAV, aroma recombination and omission tests. • Masking effects were predominant (17/28 pairs) among key odorant mixtures. • Synergism was observed specifically among structurally analogous compounds. In this study, the aroma profile of Zhoushan fish sauce and the perceptual interactions among its key odorants were characterized using Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry (SPME-GC-MS), Gas Chromatography-electronic-nose (GC-E-nose) and Feller's additive model. A total of 81 volatiles were identified, among which 15 compounds were determined as important odorants with odor activity value (OAV) greater than 1. Aroma recombination and omission experiments revealed that eight compounds made significant contributions ( p  < 0.05) to the characteristic aroma including phenylacetaldehyde (392.31 μg/L), isovaleraldehyde (93.49 μg/L), nonanal (49.49 μg/L), 3-methylthiopropanal (0.93 μg/L), benzaldehyde (273.86 μg/L), 1-hexanol (20.82 μg/L), 2-methylbutanal (109.91 μg/L) and 1-octen-3-ol (126.35 μg/L). To elucidate the interaction mechanisms, 28 binary mixtures of these key odorants were evaluated using Feller's additive model. The results revealed a distinct structure-interaction relationship: Masking effects were predominant (17/28 pairs), particularly between compounds with dissimilar chemical structures, suggesting a competitive mechanism at the olfactory receptor level. Conversely, additive or synergistic effects were observed among structurally analogous compounds, likely due to cooperative receptor activation. The σ-τ plot and molecular docking results further support this conclusion. These findings provide a theoretical basis for understanding how Strecker aldehydes mask fishy off-odors, offering new insights for the precise flavor regulation of fermented seafood products.