A climatic characterisation of the sub-Appellations in the Niagara Peninsula wine region

AIM: The current loss of genetic grapevine diversity is mainly due to the reduced number of varieties used for making wine. A way of preserved endangered varieties is the establishment of germplasm banks.

Unlike most of other foods, wine sensory quality is thought to reach a peak after an aging period. In the case of the Valpolicella red wines

Since some years, the French wine sector faces strategical challenges, all linked to climate change. Multiple issues have been observed like diseases development, early frost, drought, change in the precocity and maturity of grapes, each one resulting in loss of productivity and yield. In France, the varieties proposed today by nurseries are historical varieties that are not well adapted to those changes. Therefore, Mercier Frères, one of the leading grapevine nursery, has decided to start its own research programs, with the help of its laboratory Novatech, to answer the growing demand for new grapevine varieties.

Among the many compounds in wine, condensed tannins play an important role in the organoleptic properties of the products; they are partly responsible for astringency, bitterness and also contribute to the color. This research work aims to study the oxidation state of these bio-heteropolymers which is an important lock in the analysis of processed products in order to better control their quality. Indeed, their identification remains at present a challenge because of the large heterogeneity of their degrees of polymerization (DP) based on 4 monomers (epicatechin, catechin, epigallocatechin, epicatechin-3-O-gallate) thus multiplying the number of oxidation products.

When the cork is in direct contact with an alcoholic solution such as in case of a bottle wine, some cork components can migrate into the wine.