Oxidation in wine: Does expertise influence the perception?

Wines can develop off-odours that depreciate their quality. Among them, oxidation is one of the most prevalent. The main objective of this work was to study the perception of wine oxidation through the categorization of oxidized wines perceived as not-faulty/faulty depending on the expertise of participants. For this purpose, one white wine and one red wine were spiked with three volatile oxidation compounds (acetaldehyde, phenylacetaldehyde and methional) in order to recreate twelve levels of oxidation in a controlled way. Samples were submitted to orthonasal tasting for being categorized by wine experts and novices and coupled to a free description task. Results demonstrated that experts were significantly more consensual to categorize oxidized wines than novices. However, the difference between the two groups was not of great magnitude. To find an explanation, a posteriori individual data treatment was carried out. This analysis highlighted five particular behaviours as a function of the samples' oxidation level, irrespective of the level of expertise. Results also highlighted that for the experts, the frontier between the two categories (not-faulty/faulty) was significantly clearer for the white wine than for the red wine. This same tendency was also observed for the novices.