Effect of climate and soil on phenology and ripening of Vitis vinifera cv Touriga acional in the Dão region

Beyond the sole warming globally perceived and monitored, climate change impacts water availability. Increasing heatwaves frequency observed during the last decades

L’objectif d’une étude sur trois années vise, pour des terroirs différents et connus pour le profil des vins qui en sont issus, à exploiter au mieux le potentiel des raisins en optimisant la date de récolte ; pour chacun des trois terroirs, les minivinifications sont réalisées à partir de trois dates de récolte . Il s’avère, grâce à un suivi analytique important (sol, précurseurs et arômes) et une caractérisation organoleptique bien encadrée (analyse sensorielle pertinente et objective), que le choix de la date de récolte, en fonction du terroir, a une incidence sur le profil du vin et devient un outil pour l’élaborateur.

AIM Methyl salicylate (MeSA) has been reported as a potentially impactful compound in Verdicchio wines produced in central Italy. Lugana is another white wine produced in the north-east of Italy from a grape locally known as Trebbiano di Soave, sharing a very similar genetic background with Verdicchio. The aims of this study were evaluating MeSA occurrence in Lugana, assessing its aroma impact on white wines aroma and elucidating its biogenesis during vinification. METHODS Fifteen Lugana wines were analysed for methyl salycilate content in comparison with Verdicchio, Pinot grigio and Garganega wines. MeSA impact on white wine aroma was studied by means of triangular test, adding MeSA at different concentrations. Possible routes of MeSA formation by yeast were investigated by means of a high throughput assay in which S. cerevisiae cells were put in contact with precursor such as salicylic acid (esterification) or glycosidic extracts (glycosidase). Sub-fractions of Lugana glycosidic extracts were also obtained by HPLC fractionation, allowing further evaluation of precursors role.

Powdery mildew, caused by Erysiphe necator, is a widespread disease that causes high economical losses in viticulture. The main strategy to control the disease is the recurrent application of sulphur based phytochemical compounds. However, in order to reduce their accumulation in the environment and promote the sustainability of the sector, the European Commission has applied restrictions to the number of pesticide treatments and the maximum quantity of fungicides to be applied in viticulture. Seaweeds, in particular macroalgae, are marine resources rich in sulphated polysaccharides with bio-protective potential for the plant, representing an environmentally-friendly alternative approach for sustainable wine production.

AIM: Study the chemical and sensory parameters of fifty commercial white wines elaborated with different techniques (fermented in oak barrel and aged on lees (FB+AL); aged on lees (AL); and without aging (WA)) and different grape varieties (Verdejo, Sauvignon blanc and Godello).