Characterized one of the largest collections of grapevine rootstocks (non-vinifera)

The effect of two rootstocks of different drought tolerance (1103 Paulsen and 3309 Couderc) on sap flow, water relations and gas exchange of cv. Xinomavro (Vitis vinifera L.) was investigated during the 2005 season in Naoussa, Greece. Soil was maintained at field capacity for both rootstock treatments until mid July when a restricted water regime was applied by irrigation cutoff. Sap flow diurnals for the Xinomavro-1103P combination showed a rapid decrease of flow after midday, under water stress conditions.

Condensed tannins (also called proanthocyanidins) are a widely distributed throughout in plants kingdom and are one of the most important classes of secondary metabolites, in addition, they are part of the human diet. In wine, they are extracted during the winemaking process from grape skins and seeds. These compounds play an important role in red wine organoleptic characteristics such as color, bitterness and astringency. Condensed tannins in red wine are oligomers and polymers of flavan-3-ols unit such as catechin, epicatechin, epigallocatechin and epicatechin-3-O-gallate. The monomeric units can be linked among them with direct interflavanoid linkage or mediated by aldehydes.

In France, one of INAO missions is to delimit the production area of the « Appellations d’origine contrôlées » (AOC). For wine AOC, the delimitation of plots allows for identifying plots of land that respond to technical criteria of the vine location, criteria adapted in every appellation. Some old delimitations AOC are not in adequacy with their territory. Indeed, in spite the existence of a politic aiming to protect production areas AOC, urbanization, road infrastructure or quarries occupy surfaces classified in AOC today.

The evolution of wine during bottle ageing has been of great interest to ensure consistent quality over time. While the role of wine closures on the amount of oxygen is well-known [1], closures could also play other roles such as the scalping phenomenon of flavour compounds. Flavour scalping has been described as the sorption of flavour compounds by the packaging material, which could result in losses of flavour intensity. It has been reported in the literature that volatile sulphur compounds (VSC) can be scalped on wine closures depending on the type of closure (traditional and agglomerated cork, screw-cap, synthetic [2]).

The aim was to study the impact of structural features in the polysaccharide moiety of mannoproteins on their interaction with polyphenols and the formation of colloidal aggregates.