Characterization of bunch compactness and identification of associated genes in a diverse collection of cultivars of Vitis vinifera L.

Malolactic fermentation (MLF) is a secondary step in the vinification process and it follows alcoholic fermentation (AF) which is predominantly carried out by Saccharomyces cerevisiae. These two processes result in the degradation of metabolites to produce secondary metabolites which also contribute to the final wine flavour and quality. AF results in the production of ethanol and carbon dioxide from sugars and MLF stems from the degradation of L-malic acid (a dicarboxylic acid) to L-lactic acid (a monocarboxylic acid). The latter process results in a smoother texture as the acidity of the wine is reduced by the process, it also adds to the flavour complexity of the wine.

Condensed grape tannins play a major role in the organoleptic properties and quality of red wine. Recently, a new sub-family of macrocyclic condensed tannins has been identified in red wine and named “crown tannins”. Indeed, the first compound of the family identified and characterised by NMR was the crown procyanidin tetramer which is composed of a macrocyclic structure composed of four (-)-epicatechins link together by B-type interflavanoid linkage in the following an alternative sequences of C4-C8 and C4-C6 linkage. The 3D structure of this unusual crown procyanidin family reveals a central cavity in the molecule [1].

The increasing frequency of extreme weather events (EWE) represents a severe threat to viticulture.

Far from complicated discussions on the relevant way to define « terroir », this article deals with the social perception that French young adults (aged from 18 to 30) have of this concept and the way it can help them to become wine consumers.

Specific inactivated yeast derivatives (SYDS) are obtained from s. cerevisiae yeasts by various processes (thermal, mechanical, and enzymatic) and have diverse oenological applications to improve wine quality. However, different impacts on wine sensory and aromas were reported, depending on syds types and fractions, wine matrices, and experimental settings. Few works have examined the impact of SYDS on aromas considering also those on wine macromolecules influencing organoleptic properties.