Isolation and identification of odorants generated in wine during its oxidation: a gas chromatography-olfactometric study

The changes in the flavor profiles of several white wines undergoing oxidation were monitored through gas chromatography-olfactometry (GCO). The study showed that up to 19 odorants were generated during wine oxidation. and that several of the odorants originally present in the wine disappeared or decreased. An aroma extract dilution analysis revealed that 5 of these 19 odorants have maximum dilution factors, and that a second group of 7 may have some sensory significance as well. The isolation and identification of the different odorants was achieved via normal and reverse-phase high-performance liquid chromatography and high-resolution GCO. The impact odorants of oxidized wine were found to be 2, 4, 5-trimethyldioxolane, methional (methylthioproganal), sotolon (4,5-dimethyl-3-hydroxy-2(5H) -furanone), eugenol (4-propenyl-2-methoxyphenol) and an unknown compound with mass spectrum similar to methylvanillate. Other odorants also formed during wine oxidation were 1-octen-3-ol, t-2-nonenal, furfural, benzaldehyde, 2-butoxyethanol, acetovanillone and a dioxolane isomer.