OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 Comparing the effects of vision, smell and taste in red wine quality judgments by experts: sensory cues, mental imagery and verbal representations as drivers of consensus in the multisensory space

Comparing the effects of vision, smell and taste in red wine quality judgments by experts: sensory cues, mental imagery and verbal representations as drivers of consensus in the multisensory space

Abstract

In this study, we evaluated the contributions of vision, smell and taste to red wine quality judgments by expert wine tasters. Whereas previous studies specified the modulating effects of gustatory traits [1], culture and expertise [2, 3], our objective was to gain a better understanding of the perceptual mechanisms, with special consideration of the psychological representations that predict consensus in red wine quality judgments. To this aim, we compared wine tasters’ responses in unconstrained (i.e., all senses involved) and constrained wine tastings (i.e., unisensory: “visual”, “smell” and “taste”; multisensory: “visual-smell”, “visual-taste” and “taste-smell”) over six wine tasting sessions. In each session, wine tasters rated the quality of 20 red wines from a Protected Designation of Origin (PDO, premium vs. secondary wines), starting with an unconstrained tasting and then followed by a constrained tasting. We also collated predictors based on wine tasters’ responses to self-report questionnaires that assessed vividness of mental imagery in visual, smell, taste, somesthetic and wine contexts. Using a series of vocabulary tasks, we also evaluated whether lexical capacity predicts consensus in red wine quality judgments. 

Overall, our results showed a coherent quality concept across unconstrained and constrained wine tastings, with a clear quality distinction favoring premium wines. However, principal component analyses suggested a better quality judgement consensus with unisensory vision cues compared to all other sensory conditions. Going further, regression analyses also revealed specific drivers of red wine quality judgment consensus that are based on age, vividness of wine mental imagery, lexical capacity and consensus, as well as unisensory smell consensus and to a lesser degree, multisensory visual-taste consensus and unisensory taste consensus. 

Common experiences with wine, as well as the number of years tasting might promote strong vividness for wine representations (images and vocabulary), which in turn help predict wine tasters’ inclusion to the consensus involved with red wine quality judgments. Taken together, this study gives us an insightful look at the individual knowledge base, as well as the experience and representational cues that could delineate expert status. Further research in this direction could help promote informed teaching curricula in professional training and expert wine tasting.

[1] Saenz-Navajas, M.-P., Avizcuri, J.-M., Ballester, J., Fernandez-Zurbano, P., Ferreira, V., Peyron, D., et al. (2015). Sensory-active compounds influencing wine experts’ and consumers’ perception of red wine intrinsic quality. LWT – Food Science and Technology, 60, 400–411. 
[2] Saenz-Navajas, M.-P., Ballester, J., Pecher, C., Peyron, D., and Valentin, D. (2013). Sensory drivers of intrinsic quality of red wines: Effect of cultures and level of expertise. Food Research International, 54, 1506–1518. 
[3] Valentin, D., Parr, W. V., Peyron, D., Grose, C., and Ballester, J. (2016). Colour as a driver of Pinot noir wine quality judgments: An investigation involving French and New Zealand wine professionals. Food Quality and Preference, 48, 251-261.

DOI:

Publication date: June 19, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

André Caissie, Laurent Riquier, Gilles De Revel, Sophie Tempère

Unité de recherche Oenologie, EA 4577, USC 1366 INRA, ISVV, Université de Bordeaux, Bordeaux INP, F33882 Villenave d’Ornon France
INRA, ISVV, USC 1366 OEnologie, F-33140, Villenave d’Ornon, France.

Contact the author

Keywords

Wine tasting, Perceptual mechanisms, Mental Imagery, Vocabulary

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

First step in the preparation of a soil map of the Protected Designation of Origin Valdepeñas (Central, Spain)

This work is a first step to make a map of vineyard soils. The characterization of the soils of the Protected Designation of Origin (D.P.O.) Valdepeñas will allow to group the studied profiles according to their physico-chemical characteristics and the concentrations of most relevant chemical elements. 90 soil profiles were analysed throughout the territory and the soils were sampled and described according to FAO (2006) and classified according to and Soil Taxonomy (2014). All samples were air dried, sieved and some physico-chemical parameters were determined following standard protocols. Also, major and trace elements were analysed by X-ray fluorescence. The statistically study was made using the SPSS program. Trend maps were made using the ArcGIS program. The studied soils have the following average properties: pH, 8.3; electrical conductivity, 0,20 dS/m (low); clay, 18.8% (medium) and CaCO3, 17.1% (high). In the study for the major elements. The major elements of these soils are Si, followed by Ca and Al, with an average content of 203.7 g/kg, 105.5 g/kg and 74.0 g/kg respectively. On the other hand, 27 trace elements have been studied. Of all of them, it can be highlighted the average values of Ba (361.8 mg/kg), Sr (129.3 mg/kg), Rb (83.4 mg/kg), V (74.2 mg/kg) and Ce (70.6 mg/kg). Ba, V and Ce values are higher and the values of Sr and Rb are lower to those found in the literature. The discriminant analysis shows a percentage of grouping of 91%. The content of chemical elements together with the physico-chemical characteristics allows grouping the soils in 4 group according to their order in the classification to Soil Taxonomy; due to the importance of the Calcisols in Castilla-La Mancha, it has been decided to establish them as their own group even if they do not appear in Soil Taxonomy classification.

Climate change projections to support the transition to climate-smart viticulture

The Earth’s system is undergoing major changes through a wide range of spatial and temporal scales as a response to growing anthropogenic radiative forcing, which is pushing the whole system far beyond its natural variability. Sources of greenhouse gases largely exceed their sinks, thus leading to a strengthened greenhouse effect. More energy is thereby being supplied to the system, with inevitable shifts in climatic patterns and weather regimes. Over the last decades, these modifications have been manifested in the full statistical distributions of the atmospheric variables, with dramatic changes in the frequency and intensity of extremes. Natural hazards, such as severe droughts, floods, forest fires, or heatwaves, are being triggered by extreme atmospheric events worldwide, thus threatening human activities. Viticultculture is not only exposed to changing climates but is also highly vulnerable, as grapevine phenology and physiological development are strongly controlled by atmospheric conditions. Therefore, the assessment of climate change projections for a given region is critical for climate change adaptation and risk reduction in viticulture. By adopting timely and suitable measures, the future sustainability and resiliency of the sector can be fostered. Climate-grapevine chain modelling is an essential tool for better planning and management. However, the accuracy of the resulting projections is limited by many uncertainties that must be duly taken into account when transferring knowledge to stakeholders and decision-makers. Climate-smart viticulture will comprise ensembles of locally tuned strategies, envisioning both adaptation and mitigation, assisted by emerging technologies and decision-support systems.

The use of rootstock as a lever in the face of climate change and dieback of vineyard

As viticulture faces challenges such as climate change or vineyard dieback, the choice of the variety and rootstock becomes more and more crucial. To study rootstock levers in the Bordeaux region, a parcel of Cabernet Sauvignon (CS) was planted with four rootstocks in 2014. Twenty repetitions of each of the following four rootstocks were set up: 101-14 MGt, Nemadex AB, 420A MGt and Gravesac. The number of bunches, yields and pruning weights of the vine shoots were measured individually on 240 vines from 2017 to 2021. Since 2020, nitrogen status assessed by assimilable nitrogen level, hydric status assessed by δ13C and berry maturity were measured on 80 samples taken from 20 repetitions of the four rootstocks. A lower yield was measured for CS grafted onto Nemadex AB due to the lower number of bunches and the lower weight of berries. The differences between the other three rootstocks are small, but CS grafted onto 420A MGt was the most productive. The CS grafted onto Nemadex AB had the lowest pruning weight while 101-14 MGt had the highest. In 2020, δ13C showed a more moderate water stress with 101-14 MGt and 420A MGt than with Nemadex AB. Surprisingly, the Gravesac was under more stress than the 101-14 MGt. The nitrogen status in the berries was better for Nemadex AB but this was perhaps due to the significantly lower weight of the berries.Rootstock 101-14 MGt attained the highest accumulation of sugars in the berries while 420A MGt allows to preserve higher acidity. The parcel is still young which may explain some of the results. These measures must therefore be continued over the next several years to fully assess the effects of these rootstocks on the development of the vines and the quality of the production under new climatic conditions.

Characterization of variety-specific changes in bulk stomatal conductance in response to changes in atmospheric demand and drought stress

In wine growing regions around the world, climate change has the potential to affect vine transpiration and overall vineyard water use due to related changes in atmospheric demand and soil water deficits. Grapevines control their transpiration in response to a changing environment by regulating conductance of water through the soil-plant-atmosphere continuum. Most vineyard water use models currently estimate vine transpiration by applying generic crop coefficients to estimates of reference evapotranspiration, but this does not account for changes in vine conductance associated with water stress, nor differences thought to exist between varieties. The response of bulk stomatal conductance to daily weather variability and seasonal drought stress was studied on Cabernet-Sauvignon, Merlot, Tempranillo, Ugni blanc, and Semillon vines in a non-irrigated vineyard in Bordeaux France. Whole vine sap flow, temperature and humidity in the vine canopy, and net radiation absorbed by the vine canopy were measured on 15-minute intervals from early July through mid-September 2020, together with periodic measurement of leaf area, canopy porosity, and predawn leaf water potential. From this data, bulk stomatal conductance was calculated on 15-minute intervals, and multiple regression analysis was performed to identify key variables and their relative effect on conductance. Attention was focused on addressing multicollinearity and time-dependency in the explanatory variables and developing regression models that were readily interpretable. Variability of vapor pressure deficit over the day, and predawn water potential over the season explained much of the variability in conductance, with relative differences in response coefficients observed across the five varieties. By characterizing this conductance response, the dynamics of vine transpiration can be better parameterized in vineyard water use modeling of current and future climate scenarios.

Ecophysiological performance of Vitis rootstocks under water stress

The use of rootstocks tolerant to soil water deficit is an interesting strategy to cope with limited water availability. Currently, several nurseries are breeding new genotypes, but the physiological basis of its responses under water stress are largely unknown. To this end, an ecophysiological assessment of the conventional 110-Richter (110R) and SO4, and the new M1 and M4 rootstocks was carried out in potted ungrafted plants. During one season, these Vitis genotypes were grown under greenhouse conditions and subjected to two water regimes, well-watered and water deficit. Water potentials of plants under water deficit down to < -1.4 MPa, and net photosynthesis (AN) <5 μmol m-2 s-1 did not cause leaf oxidative stress damage compared to well-watered conditions in any of the genotypes. The antioxidant capacity was sufficient to neutralize the mild oxidative stress suffered. Under both treatments, gravimetric differences in daily water use were observed among genotypes, leading to differences in the biomass of root, shoot and leaf. Under well-watered conditions, SO4 and 110R were the most vigorous and M1 and M4 the least. However, under water stress, SO4 exhibited the greatest reduction in biomass while M4 showed the lowest. Remarkably, under these conditions, SO4 reached the least negative stem water potential (Ψstem), while M1 reduced stomatal conductance (gs) and AN the most. In addition, SO4 and M1 genotypes also showed the highest and lowest hydraulic conductance values, respectively. Our results suggest that there are differences in water use regulation among genotypes, not only attributed to differences in stomatal regulation or intrinsic water use efficiency at the leaf level. Therefore, because no differences in canopy-to-root ratio were achieved, it is hypothesized that xylem vessel anatomical differences may be driving the reported differences among rootstocks performance. Results demonstrate that each Vitis rootstock differs in its ecophysiological responses under water stress.