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 sigma-tau 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.