Molecular characterization of a variegated grapevine mutant cv Bruce’s Sport

Fining is a technique that is used to remove unwanted wine components that affect clarification, astringency, color, bitterness, and aroma. Fining involves the addition of adsorptive or reactive material in order to reduce or eliminate the presence of certain less desirable wine components and to ensure that a wine remains in a particular stable state for a given period of time Recently concerns have been raised about the addition of animal proteins, such as gelatin, to wine due to the disease known as bovine spongiform encephalopathy (Mad Cow disease). Although the origin of gelatins has been moved to porcine, winemakers are asking for substitute products with properties and application protocols similar to the traditional animal-derived ones, making the use of plant-derived proteins in fining a practically viable possibility. As a consequence, various fining agents derived from plants have been proposed, including proteins from cereals, legumes, and potato.

With the steady rise in wildfire occurrence in wine regions around the world, there are quality issues beginning to face the wine industry. These fires produce clouds of smoke which have the ability to carry organic molecules across vast distances that can be absorbed by grapes. When these compounds make their way into the final wine, unpleasant smokey and burnt flavors are present, along with a lasting ashy finish. Along with the volatile compounds carried by smoke, once incorporated into the fruit these compounds become bound to sugars, forming glycosidic compounds.

La quantité et la qualité des flavonoïdes sont des éléments importants de la qualité de la baie. En particulier, les tannins contribuent de manière essentielle aux propriétés spécifiques des vins rouges telles que la couleur, l’astringence et l’amertume. Cependant, leur synthèse et leurs propriétés sont encore mal connues. Ainsi, la

Proteins constitute one of the three main components of grape juice and white wine, phenolic compounds and polysaccharides being the others. A specific group of the total grape-derived proteins resists degradation or adsorption during the winemaking process and remains in finished wine if not removed by the commonplace commercial practice of bentonite fining. While bentonite is effective in removing the problematic proteins, it is claimed to adversely affect the quality of the treated wine under certain conditions, through the removal of colour, flavor and texture compounds. A number of studies have indicated that different protein fractions require distinct bentonite concentrations for protein removal and consequent heat stabilization.

The use of toasted vine-shoots as an alternative enological tool to make differentiated wines has generated interest among researchers and wineries. However, the evolution of these wines in bottle and the effect on the sensory profile has not been studied so far.