Identifying research opportunities at Douro Demarcated Region

With climate change, it is progressively more often to obtain grapes with an acceptable content in sugars or acids but with immature tannins described as green, aggressive or hard (noted as GAH onwards). During winemaking, the oenologist has to make decisions related to the elaboration of such grapes based mainly on empirical experience, given the lack of objective criteria to this concern. An increase in the chemical and sensory knowledge of immature tannins would allow managing this GAH character of grapes with the maximum possible efficiency during winemaking processes. The present work aims at isolating and identifying the group of compounds responsible for the GAH character present in wines.

In mediterranean agriculture, sustainability and productivity are seriously threatened by climate change and water scarcity. This situation is exacerbated by poor management practices such as excessive use of agrochemicals, overgrazing, and monoculture. The Douro demarcated region (ddr) is an emblematic region, classified world heritage site by UNESCO in 2001. Viticulture is the main agricultural activity in DDR, widely known to produce port wine.

Champagne or sparkling wines elaborated through the same traditional method, which consists in two major yeast-fermented steps, typically hold about 10 to 12 g/L of dissolved CO2 after the second fermentation in a closed bottle. Hundreds of molecules and macromolecules originating from grape and yeast cohabit with dissolved CO2; they are essential compounds contributing to many organoleptic characteristics (effervescence, foam, aroma, taste, colour…). Indeed, the second alcoholic fermentation and the maturation on lees (which may last from 12 months up to several years) both induce various quantitative and qualitative changes in the wine through the action of yeast, as listed hereafter: development of aromas during aging on lees, release of nitrogen compounds during autolysis and release of macromolecules (polysaccharides, lipids, nucleic acids) in wine.

La superficie vitata della provincia di Modena é per circa il 70% interessata dai Lambruschi, famiglia di vitigni tipica dei territori pianeggianti emiliani. Tra questi, i più rappresentativi sono il Lambrusco di Sorbara, il Lambrusco salamino e il Lambrusco grasparossa che, unico esempio, predilige gli ambienti collinari della provincia. Nel quinquennio 2001-2005 la Provincia di Modena ed il C.R.P.V. hanno coordinato la zonazione viticola di tutto il territorio dei Lambruschi modenesi, i cui risultati hanno consentito di individuare, in ciascuna zona D.O.C., alcune Terre in cui cias.

The effects of different methods of soil management on the nutrient supply and the wine quality of organically grown Grüner Veltliner grapevines (wide-spaced high culture training system) were investigated in the winegrowing region Wagram of Lower Austria (municipality: Großriedenthal).