Molecular descriptors of icewine odorants: A first insight into their relationship with metabolism and olfactory perception.

Abstract

To investigate the differences in physicochemical parameters of compounds that are metabolized from different precursors and contribute to the aroma perception of icewine, odor-active compounds in icewine were identified by gas chromatography-olfactometry (GC-O) analysis combined with comprehensive two-dimensional GC and time-of-flight mass spectrometry (GC × GC-TOFMS) analysis, and the molecular descriptors of these odor-active compounds were calculated by computational chemistry software. The distribution pattern of these odorants classified by their precursors and their olfactory perception was visualized on the basis of their molecular descriptor differences. The results showed that the odorants sourced from different precursors could be clearly separated from each other based on their molecular descriptors, which belonged to blocks such as constitution indices and 2D matrix-based descriptors. The results also showed that honey and cooked potatoe descriptions or peach and smoke descriptions have quite different molecular descriptors. This study should contribute to future research that relates to computational chemistry-based aroma perception and prediction in fermented beverages. PRACTICAL APPLICATION: The results obtained from this study may be useful for the construction of a classification system of various odor-active compounds in a given product and may provide a molecular solution for the determination of different perceptual dimensions of an odor mixture.