Does wine expertise influence semantic categorization of wine odors?

Abstract

Aromatic characterization is a key issue to enhance wines knowledge. While several studies argue the importance of wine expertise in the ability of performing odor-related sensory tasks, there is still little attention paid to the influence of expertise on the semantic representation of wine odors. Theis study aims at exploring the influence of subject’s expertise on the semantic space of wine’s odor. 

156 subjects were recruited (72 % consumers of wine and 28 % professionals from viticulture sector). Subject’ level of expertise was measured by means of a questionnaire encompassing three criteria: product experience, subjective knowledge and objective knowledge. Four groups of subjects were identified using Rasch model corresponding to four levels of expertise: novices, intermediates, connoisseurs and experts. Thereafter, subjects performed a sorting task on 96 labels of odors and add a title to the groups. To investigate the influence of subject’s expertise on the semantic space of wine’s odor, the four groups’ clusters were compared on several criteria: number and size of odor groups from the sorting task and agreement between the subjects within each cluster. Dissimilarity matrices were also compared to highlight differences between clustering. Finally, to represent the semantic odor space, additive similarity trees were performed on sorting data. 

Results show that number and size of odor groups are likely to be the same between the four clusters (between 26 and 31 groups in average and 3 odors per group in average for the four clusters) and no differences of agreement within each cluster can be highlighted. Additive trees performed on clusters show that most of the branches are the same between the two clusters: fruity, floral, woody, vegetal, spicy, etc. Overall, semantic representation of odors is consensual regardless the level of expertise. But, some differences may be underscored. These latter ones are mostly between expert’s cluster and the three other clusters. 

This work highlights that subjects, professionals or not, have the same structuration of wine odor attributes: they categorize odors according to the odorant source. However, some attributes do not have the same meaning for experts and non-experts which lead to a different categorization. This study is the first step toward a sensory tool for wine characterization aiming at simplifying and standardizing the process of describing wine odors, from generic to more specific attributes.