Wine bouquet: the perceptual integration of chemical complexity

Although hundreds of chemical compounds have been identified in grapes and wine, it has been repeatedly demonstrated that only a small fraction of these compounds in reality contribute to the flavor of wine. These compounds have the ability to activate at least one of the chemical senses located in the mouth and in the nose. Even if the actual number of flavor compounds is reduced, when compared to wine chemical complexity, the mixture of stimuli is transformed into a mixture of sensory signals that is integrated all along the sensory pathways to give rise to the wine’s bouquet. During this integration process, perceptual interactions, within and between senses, are likely to occur [1]. Being a very specific food product, wine may be tasted twice - firstly with the nose and secondly once in the mouth. Beyond the differences in terms of physico-chemical characteristics between these two tasting conditions (e.g. temperature or saliva), there are also differences in terms of the senses that can be activated (e.g. taste or retronasal olfaction). As a consequence, the integration process is very different between these two tasting conditions [2]. The integration of perceptually active compounds in wine, associated to perceptual interactions (e.g. masking, sub-threshold synergy, cross-modal enhancement) is reviewed using examples linked to wine flavor, and its consequences, both in terms of flavor analysis and actual perception, are discussed