Variabilité spatiale du gel printanier dans le vignoble champenois : application au zonage climatique

In questa nota viene analizzata l’importanza della conoscenza del territorio nel funzionamento del mercato dei prodotti alimentari di qualità e nella gestione delle denominazioni di origine.
La denominazione di origine si sta affermando in tutti i mercati alimentari, dopo l’esperienza secolare maturata nel mercato del vino. Iniziative nel campo del turismo, delle produzioni ecologiche, della promozione dello sviluppo, sono collegate alla dimensione territoriale, in risposta ad un generale orientamento della domanda.

ulfur compounds in wine have been studied for several years due to their impact on wine flavour, but the role of polysulfides is a recent topic. Polysulfides in wine are formed when two sulfhydryl groups oxidize, especially in presence of elemental sulfur or metal catalysts from field treatment residues (Ugliano et al. 2011). These compounds are odourless, but can degrade during storage and affect the wine quality. The mechanism of their formation is still largely unknown but different chemical and biochemical pathways have been suggested. Disulfides from cysteine (Cys) and glutathione (GSH) have been revealed in model wines (Kreitman et al. 2016) and more recently also higher polymerized forms in real wines (Van Leeuwen et al. 2020). Volatile varietal thiols like 3-mercaptohexanol (3MH) and 4-mercaptopentanone (4MMP) – flavour compounds with tropical or fruity notes – could undergo similar reactions, also with Cys and GSH, subsequently losing their flavour property (fate). Even more concerning is the possible release of H2S from polysulfides during storage, leading to undesired off-flavours (Sarrazin et al. 2010).

Wine consumers generally demand wines having a perception of softer tannins and less ripe, having a heaviness and richness on palate (full-body wine) with a limpid and stable color. However, polyphenol
(tannins)-rich wines have been also correlated with unpleasant taste properties such as astringency and
bitterness when perceived at high intensities. Modulating these unpleasant properties could be important for consumer’s approval of wines.

Par le fait d’une politique agricole communautaire axée sur des objectifs de qualité des produits, la recherche et l’identification des critères de cette qualité deviennent impératives. En viticulture, la notion de qualité du produit est rattachée au concept théorique de «terroir». Ce terme englobe un ensemble de paramètres du milieu (géologie, sol, climat) influant sur la récolte.

Le zonage agroclimatique a pour objet de caractériser des lieux ayant des aptitudes distinctes pour la production de la vigne. La province de San Juan en Argentine est l’une des régions vitivinicoles les plus chaudes du pays.