Evaluation of the Perceptual Interactions Between Higher Alcohols and Off-Odor Acids in Laimao Baijiu by σ–τ Plot and Partition Coefficient

The volatile compounds in three Laimao baijius ("Chuanchenglan, CCL", "Hongyu, HY", and "Zhencang, ZC") were comprehensively analyzed by gas chromatography-olfactometry and gas chromatography-mass spectrometry. The results demonstrated that 44, 42, and 42 compounds with flavor dilution factors ≥ 16 and odor activity values ≥ 1 were, respectively, identified as important odorants. Additionally, the perceptual interactions of 6 higher alcohols and 3 off-odor acids were evaluated by σ-τ plot, and the partition coefficient was calculated to explain the release of odorants in the matrix. The interactions indicated that adding a high concentration of 1-propanol or 2-phenylethanol to the matrix could mask the sweaty note of 3-methylbutyric acid. The partition coefficients explained that high concentrations of 1-propanol and 2-phenylethanol were able to significantly inhibit the release of 3-methylbutyric acid when the phase ratio was relatively large, and the effect of 1-propanol on it was higher than that of 2-phenylethanol.