Kinetic investigations of the sulfite addition on flavanols

Originaire du bassin lémanique, le chasselas est l’emblème de la viticulture suisse. Pour autant, les surfaces de chasselas n’ont cessé de diminuer, passant de 6’585 hectares en 1986 à près de 3’600 aujourd’hui, reflet d’une baisse de consommation. Une récente étude a cherché à comprendre les raisons de ce désintérêt. Réalisée dans

During oak wood contact, wine undergoes important modifications that modulate its organoleptic quality and complexity, including its aroma, structure, astringency, bitterness and color. Vescalagin and castalagin are the two main C-glucosidic ellagitannins found in oak wood used for wine aging wood but lyxose/xylose derivatives (grandinin and roburin e) and dimeric forms (roburins a,b, c and d) are also present. The presence of several hydroxyl groups in the ortho-positions at the periphery of the structure of the ellagitannin isomers allows these molecules to undergo oxidation or condensation reactions with other compounds.

Grapevine powdery mildew resistance is a key target for grape breeders and grape growers worldwide. The driver of the USDA-NIFA-SCRI VitisGen3 project is completing the pipeline from germplasm identification to QTL to candidate gene characterization to new cultivars to vineyards to consumers. This is a common thread across such projects internationally. We will discuss how our objectives and approaches leverage big data to advance this initiative, starting with genomics and computer vision phenotyping for gene discovery and genetic improvement. To manage and maintain resistances for long-term sustainability, growers will be trained through our nation-wide extension and outreach plan.

Aging wine on lees is a consolidated practice during which some yeast components (e.g., polysaccharides,
proteins, peptides) are released and solubilized in wine thus, affecting its stability and quality.
Apart from the widely studied mannoproteins, the role of other yeast components in modulating wine
characteristics is still scarce. Wine peptides have been studied for their contribution to taste, antioxidant,
and antihypertensive potentials. However, the peptides detected in wine can be influenced by the
interaction between yeasts and grape components.

Wine by-products valorisation by green chemistry methods: Impact of the extraction process on the structure, functionalities and activity of the extracted molecules