Étude des potentialités des terroirs viticoles: une démarche globale en zone A.O.C. L’exemple des Côtes du Rhône

The Maillard reaction (MR) is a non-enzymatic reaction between reducing sugars and amino acids, resulting in the production of volatile and flavour-active compounds.

Les approches du terroir en tant qu’entité géographique (zonages) connaissent un développement accru récent en lien avec l’essor des SIG. Les méthodes, les objectifs et les critères utilisés varient considérablement selon les études.

Today’s viticulture faces a considerable challenge dealing with fungal diseases and limitations on the use of plant protection products (PPP) have increased the pressure to find more sustainable alternatives. One strategy may be the development and cultivation of disease-resistant grapevine varieties (PIWI) that could maintain crop productivity and quality while reducing dependence on PPP. In this work a set of 9 PIWI varieties (5 white and 4 red) deploying genes for resistance to powdery and downy mildew were evaluated in two consecutive years in Valdegón, La Rioja, with Tempranillo and Viura as controls. The objective was to correlate agronomic performance and disease incidence with the presence of disease resistance genes in two different seasons: with (2023) and without disease pressure (2022).

Aim: Wine aromatic profile is a combination of viticulture and oenological practices and it is related to character, quality, and consumer acceptance. Based on the competition between soil capacity and canopy development, and on the potential to produce sparkling wines at Caldas, in the south region of Minas Gerais (Brazil) (21°55´S and 46°23´W, altitude 1.100m), the aim of this work was the evaluation of the development of aromas (secondary metabolites) from grapes to sparkling wines in a vine-spacing experiment and whether the distance between the vines can influence the aromatic profile of the sparkling wines (final product). 

Antagonistic yeasts applied to wine grapes must be compatible with the thereafter winemaking process, avoiding competition with the fermentative Saccharomyces cerevisiae or affecting wine flavour. Therefore, fifteen epiphytic yeasts (6 Metschnikowia sp., 6 Hanseniaspora uvarum, 3 Starmerella bacillaris) previously selected for its biocontrol ability against Alternaria on wine grapes were evaluate for possible competition with S. cerevisiae by the Niche Overlap Index (NOI) employing YNB agar media with 10 mM of 17 different carbonate sources present in wine grapes (proline, asparagine, alanine, glutamic acid, tirosine, arginine, lisine, methionine, glicine, malic acid, tartaric acid, fructose, melibiose, raffinose, rhamnose, sucrose, glucose).