Characterization of Potent Odorants Causing an Oily Odor in Rice-Made Baijiu by Comparative Aroma Extract Dilution Analysis, Quantitative Measurements, and Aroma Addition and Omission Studies

The presence of an oily odor in rice-made Baijiu is a unique characteristic that has not been thoroughly studied. This study qualitatively and quantitatively identified important aroma-active compounds in samples with typical and atypical oily odors using aroma extract dilution analysis (AEDA). By comparing the differences between flavor dilution (FD) and odor activity values (OAVs), nine compounds showing significant differences were selected. By combining normal-phase silica gel column and sensory analysis, these nine potential oily odor compounds were isolated from the typical oily odor sample. Addition and omission experiments confirmed that hexanal, <i>trans</i>-2-heptenal, <i>trans</i>,<i>trans</i>-2,4-nonadienal, (2<i>E</i>)-2-decenal, <i>trans</i>,<i>trans</i>-2,4-decadienal, and γ-nonanolide are key contributors to the oily odor.