Understanding intrinsic quality assessment of red wines by experts

Abstract

Colour, aroma or in-mouth properties have been confirmed to play an important role on intrinsic quality judgments of wine. However, little is known about the relative weight the different stimuli have on the global quality perception. In this context, the present work is mainly driven for further understanding the strategy used by experts when evaluating wine quality. More specifically, the first aim is to evaluate the contribution of the different sensory stimuli to global quality evaluation and then to relate wine attributes (appearance, aroma, in-mouth) to expert responses towards global quality perception. Therefore, a panel of 21 established wine experts were asked to score the wine quality (10cm-anchored line scale) of 16 Spanish red wines in four sessions under different conditions: (1) in dark glasses: experts evaluated wine attending exclusively to orthonasal aroma properties (Quality aroma-Qa-); (2) in clear glasses: experts scored quality based on exclusively visual stimuli (Quality visual-Qv-); (3) in dark glasses: experts had to taste each wine with a nose clip, to avoid aroma and visual interactions, and scored quality based on perceived in-mouth properties (Q in-mouth-Qm); (4) in clear glasses: participants had access to visual, aroma and in-mouth cues for evaluating the global quality (Quality global-Qg-) of wines, as in conventional tastings. In parallel, a trained sensory panel formed by more than 40 participants described the orthonasal (frequency of citation method) and in-mouth sensory properties of the wines. Wine colour properties were measured by CIELab model system. The panel of experts shows a good alignment in the quality concept based on orthonasal aroma and visual cues, having both of them an important weight in global quality assessment. On the contrary, experts have a heterogeneous in-mouth quality concept and three clusters were identified. Quality mapping has been further applied for disclosing the specific sensory drivers (aroma, in-mouth and colour) of global quality perception.