Is wine an emotional object? Measurements of the subjective and automatic components of emotions in a wine-tasting situation

Wine is often described with emotional terms, such as surprising, disappointing, or pleasant. However, very little has been done to understand the role of emotions in wine tasting and characterise this link between emotions and wine. Many studies have looked at the extrinsic factors that can improve the emotional experience of tasters when discovering a wine, but few have been carried out on the emotional impact of the organoleptic characteristics of wines. The present study aims to determine if the automatic component of emotion has a measurable output (motor and physiological) when tasting wine. If so, does wine tasting induce a concomitant activation of the different components of emotion, such as subjective feelings or physiological and motor responses? Sixty-five connoisseurs tasted seven different red Bordeaux wines with different sensory properties and quality levels pre-defined by wine experts. Emotions were measured using subjective (subjective feelings measurement using self-declarative questionnaires) and automatic (physiological measurements such as skin conductance and heart rate, or motor measurements through facial expressions) methods. The results showed that there was a measurable physiological and motor emotional output in wine tasting. The results also highlighted that changes in the autonomic nervous system in a wine-tasting situation are structured around the dimensions of pleasantness and arousal. Motor measurements taken through facial expressions showed a marginally significant difference between wines providing pleasant and unpleasant emotions for the activation intensity of action units. The relationships established between these components, as well as their concomitant activation, allow us to define wine as an emotional object

Tissue-specific stilbene accumulation is an early response to wounding/grafting as revealed by using spatial and temporal metabolomics

Grafting is widely used in horticulture. Shortly after grafting, callus tissues appear at the graft interface and the vascular tissues of the scion and rootstock connect. The graft interface contains a complex mix of tissues, we hypothesised that each tissue has its own metabolic response to wounding/grafting and accumulates different metabolites at different rates. We made intact and wounded cuttings and grafts of grapevine, and then measured changes in bulk flavonoid, phenolic acid and stilbenoid concentration and used metabolite imaging to study tissue‐specific responses. We show that some metabolites rapidly accumulate in specific tissues after grafting, for example, stilbene monomers accumulate in necrotic tissues surrounding mature xylem vessels. Whereas other metabolites, such as complex stilbenes, accumulate in the same tissues at later stages. We also observe that other metabolites accumulate in the newly formed callus tissue and identify genotype‐specific responses. In addition, exogenous resveratrol application did not modify grafting success rate, potentially suggesting that the accumulation of resveratrol at the graft interface is not linked to graft union formation. The increasing concentration of complex stilbenes often occurs in response to plant stresses (via unknown mechanisms), and potentially increases antioxidant activity and antifungal capacities

Two different Oenococcus oeni lineages are associated to either red or white wines in Burgundy: genomics and metabolomics insights

Oenococcus oeni is the bacterium most often associated with spontaneous malolactic fermentation (MLF) of wine. During MLF, malic acid is transformed into lactic acid and several metabolites are modified, modulating wine’s total acidity and improving its sensory properties. Previous works have suggested that certain genetic groups of O. oeni strains are associated to different kinds of products. In the present study we have spotted two groups of strains isolated mainly from Burgundy wines, one associated to red wines and the other to white wines. Sequencing 14 genomes of red and white wine strains revealed that they share a common ancestor that probably colonised two different substrates –red and white wine-associated environments–, diverging over time and disseminating to various regions. Their capacity to perform MLF and modify the volatile profile of wine was determined by fermenting a chardonnay wine and analysing its volatile fraction with a non-targeted metabolomics approach by GC-MS. The strains had a different impact on the volatile composition depending on their group of origin. These results show for the first time a correspondence between the product of origin of the strains and the volatile profile of the wines they produce. Furthermore, the genetic features that might be implied in these different phenotypes are examined

Performing an olfactory-gustatory test to identify perceptual disorders related to Covid-19

Article dans une revue professionnelleL’un des symptômes caractéristiques causés par le SARS-CoV-2 est une altération totale ou partielle de l’odorat liée ou non à une altération du goût. La durée de cette altération semble varier d’une dizaine de jours à plusieurs semaines. Il est vrai qu’il n’est pas toujours évident, dans notre quotidien, de s’auto-évaluer et d’observer la diminution ou le changement de nos acuités olfactives et/ou gustatives. Il est pourtant simple de mettre en œuvre un test olfacto-gustatif efficace pour vous tester.One of the characteristic symptoms caused by SARS-CoV-2 is a totally or partially altered sense of smell; which may or may not be combined with an altered sense of taste. This alteration appears to last anywhere from ten days to several weeks. It’s not always easy, in our daily routines, to self-assess and notice a decline or change in the acuity of our sense of smell or taste. Yet, performing an effective olfactory-gustatory test is quite straightforward

Recovery of olfactory capacities : a special training is possible for wine professionals

Article dans une revue professionnell

Activités glycosidases chez Œnococcus œni (importance dans la libération de la vanilline à partir de bois de chêne)

Les bactéries lactiques (BL) réalisant la fermentation malolactique (FML) ont une influence significative sur la stabilité et la qualité organoleptique du vin. La FML peut être réalisée en barriques et l'influence de cette pratique sur la modification des teneurs en composés volatils du bois de chêne est étudiée dans ce travail. Nous avons montré qu'Oenococcus oeni était capable d'augmenter les teneurs en compoosés volatils du bois de chêne lors de la FML. Cette libération est importante, en particulier pour la vanilline, lorsque le métabolisme bactérien est le plus actif. L'enrichissement persiste au cours de l'élevage et participe ainsi à la complexité aromatique du vin fini. Cette libération indique la présence de précurseurs dans le bois de chêne et l'aptitude enzymatique pour OE. oeni de les métaboliser en molécules volatiles. Plusieurs hypothèses ont été envisagées et la présence de précurseurs glycosylés a été retenue, aussi bien pour la vanilline que pour d'autres composés issus du bois comme certains aldéhydes phénoliques mais aussi l'eugénol, l'isoeugénol ou la whiskylactone. L'action de glycosidases sur la vanilline libérée a été étudiée et cet aldéhyde est présent dans les extraits de bois sous formes monoglycosidiques où les groupements glycones majoritaires sont l'arabinose et le xylose. Les BL possèdent des activités glycosidases largement répandues au niveau de l''espèce OE. oeni mais avec une grande variabilité intraspécifique. Cette activité serait à l'origine des teneurs en vanilline libérées pendant la FML. Enfin, la purification de l'a-L-arabinosidase impliquée dans l'hydrolyse de la vanilline chez cette espèce a été initiée.Lactic acid bacteria (LAB) conducting the malolactic fermentation (MLF) have a significant influence on the stability and organoleptic quality of wine. The MLF can be performed in barrels and the influence of this practice on the modification of the levels of oak wood volatile compounds is also studied in this work. We showed that Oenococcus oeni was able to increase the levels of oak wood volatile compounds during the malolactic fermentation. This release is important, particularly for vanillin when LAB metabolism is the most active. Enrichment persists during the ageing and contributes to the aromatic complexity of wine. This release indicates the presence of precursors in oak wood and the production of enzymes by this species that affect vanillin formation. Several mechanisms were considered and the presence of glycosylated precursors were investigated, as well as vanillin for other oak wood compounds such as phenolic aldehydes and also eugenol, isoeugenol or the whiskylactone. The effect of glycosidases on the released vanillin was studied and this aldehyde is present in wood extracts in monoglycosidic forms where the major glycones are the arabinose and the xylose. The LAB have widespread glycosidase activities within the species O. oeni but with a great variability. This activity causes the release of vanillin during MLF. Lastly, the purification of the a-L-arabinosidase involved in the hydrolysis of vanillin in this species was initiated.BORDEAUX2-BU Santé (330632101) / SudocBORDEAUX1-BU Sciences-Talence (335222101) / SudocVILLENAVE D'ORNON-Bib. ISVV (335502201) / SudocSudocFranceF

Etude de la synthèse des composés soufrés volatils issus du catabolisme de la méthionine par Œnococcus œni

La fermentation malolactique assurée par les bactéries lactiques est à l'origine de modifications organoleptiques significatives impliquées dans la qualité du vin. Les molécules les plus étudiées sont celles issues du métabolisme des sucres et des acides organiques. L'arôme lactique caractérisé par des notes lactique et beurrée peut être enrichi et complexifié par la présence de composés soufrés volatils (CSV) dont le méthionol et l'acide 3- (méthylthio)propionique (MTPA). L'aptitude des bactéries lactiques à métaboliser la méthionine en CSV a été confirmée en particulier chez l'espèce Œ. œni. En condition œnologique, la synthèse de méthionol et de MTPA apparaît non systématique et souche dépendante. Le méthanethiol, souvent impliqué dans le défaut de réduction des vins, est synthétisé par les bactéries lactiques en conditions de laboratoire. Une implication enzymatique dans la conversion du KMBA en méthanethiol est suggérée chez Œ. œni IOEB 8406 ainsi que chez L. brevis IOEB 9901 et L. hilgardii IOEB 9109. Le méthionol est issu de la réduction du méthional et l'enzyme impliquée dans la réduction chez Œ. œni IOEB 8406 a été partiellement purifiée. Ce travail a permis d'aboutir à sa caractérisation enzymatique et à l'identification du gène. L'existence de deux voies dans la synthèse du MTPA a été montrée chez Œ. œni IOEB 8406. La présence de la voie de la décarboxylation oxydative du KMBA en MTPA a été mise en évidence mais le MTPA peut également être produit par oxydation du méthional. L. brevis IOEB 9901 et L. hilgardii IOEB 9109 sont aussi capables de former cet acide par décarboxylation oxydative alors que cette voie semble peu impliquée chez L. plantarum IOEB 9924.VILLENAVE D'ORNON-Bib. ISVV (335502201) / SudocSudocFranceF

First identification of three p -menthane lactones and their potential precursor, menthofuran, in red wines

International audienceThe p-menthane lactones constitute a family of powerful odorants, including the isomers of mintlactone and menthofurolactone that occur naturally in peppermint oil, known for their potent, mint-like olfactory properties. These lactones are closely related to the monoterpene-limonene secondary biotransformation and menthofuran has been identified as their common precursor in Mentha species. Using targeted GC-olfactometry and GC-MS analyses, together with quantification methods, we were able to demonstrate, for the first time, the presence of the diastereoisomers of these p-menthane lactones, as well as their common precursor, menthofuran, in red wines. In addition, we linked the presence of those lactones to interesting odorant zones, reminiscent of mint, detected in the studied wine. Although these p-menthane lactones may contribute individually to mint and coconut odors, sensory studies suggested for the first time that their combination at the levels found in the red wine studied resulted in a significant accentuation of freshness and mint notes