Historical zoning in the world

Port is a fortified wine, produced from grapes grown in the demarcated Douro region. The fortification process consists in the addition of a grape spirit (77% v/v) to the fermenting juice for fermentation interruption, resulting in remaining residual sugars in the wine and increased alcohol content (19-22%). The approval of grape spirits follows the Appellation (D.O. Port wine) rules1 and it is currently carried out based on analytical control and on sensory evaluation done by the public Institute that upholds the control of the quality of Douro Appellation wines. However, the producers of Port wines would like to have more information about quality markers of grape spirits.

Les effets de l’état hydrique et de l’alimentation en azote sur le potentiel aromatique des raisins de Sauvignon blanc ont été mesurés sur des vignobles du Bordelais. Les déficits hydriques ont été caractérisés par le potentiel tige déterminé en milieu de journée ΨTmin)­. L’alimentation en azote a été étudiée à partir d’une zone carencée en azote. Une part de cette zone a été supplémentée avec de l’azote minéral.

Brettanomyces yeast can negatively impact the quality and stability of wines, posing a significant challenge to winemakers. [1] This study aims to develop novel management practices to limit Brettanomyces impact on wines by evaluating the effectiveness of electrodialysis (ED) technology in removing magnesium (Mg2+) from wine to prevent the development of Brettanomyces yeast. The ED technique utilizes charged membranes to extract ions from the wine, and it is considered an alternative to cold stabilization that requires less energy. [2]

Copper in white wine can be associated with Cu(II) organic acids (Cu fraction I), Cu(I) thiol species (Cu fraction II), and Cu sulfides (Cu fraction III). The first two fractions are associated with the repression of reductive aromas in white wine, but these fractions gradually decrease in concentration during the normal bottle aging of wine. Although exposure of white wine to fluorescent light is known to induce the accumulation of volatile sulfur compounds, causing light-struck aroma, the influence on the loss of protective Cu fractions is uncertain. Riboflavin is known to be a critical initiator of photochemical reac-tions in wine, but the rate of its decay under short-term light exposure in different coloured bottles and for wine of different oxygen concentrations is not well understood.

Oenococcus oeni is the main lactic acid bacteria (LAB) species which conducts the malolactic fermentation (MLF) in wine. During MLF, O. oeni converts malic acid into lactic acid, which modulates wine aroma composition leading to better balanced organoleptic properties. O. oeni is a highly specialized species only detected in environments containing alcohol such as wine, cider or kombucha. Genome analysis of more than 240 strains showed that they form at least 4 main phylogenetic lineages and several sublineages, which are associated with different beverages or types of wines.