Comportement hydrique des sols viticoles et leur influence sur le terroir

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].

Currently, climate change represents one of the major issues for the wine sector. The increasing temperature already recorded and expected in the upcoming years reduce the vegetative cycle of the grape varieties planted in Bordeaux area, affecting the physicochemical parameters of grapes and consequently, the quality of wine. From a sensory point of view, the attenuation of the fresh fruity character in some varietals is accompanied by the accentuation of dried-fruit notes [1]. As a new adaptive and ecological strategy on global warming, some winegrowers have initiated changes in the Bordeaux blend of vine varieties using late-ripening grape varieties [2]. 

Stems may bring various benefits to the wine such as alcoholic reduction, color protection or improvement of the tannic intensity.

Un peu d’histoire pour nous efforcer de mettre le sujet des appellations dans un contexte général. Six cents ans avant Jésus-Christ, le Côte du Rhône était plantée en vignes peu après l’arrivée des Grecs

Measuring the effect of oxygen consumption on the color of wines as the level of dissolved oxygen decreases over time is very useful to know how much oxygen a wine can consume without significantly altering its color. The changes produced in wine after being exposed to high oxygen concentrations have been studied by different authors, but in all cases the wine has been analyzed once the oxygen consumption process has been completed. This work presents the results obtained with the use of an equipment designed and made to measure simultaneously the level of dissolved oxygen and the spectrum of the wine, during the oxygen consumption process from saturation levels with air to very low levels, which indicate the total consumption of the dosed oxygen[1,2].