Le zonage viticole: instrument pour la récuperation d’un ancien cépage des collines de Conegliano (Verdiso – V. vinifera)

Aim: Early leaf removal, generally applied before flowering, is mostly conceived as a technique to control grape yield and improve the health of grapes and focused on the final objective of increasing wine quality.

Wine aroma is influenced by several viticultural and oenological factors. In this study we used experimental wine making in a full factorial design to determine the impact of grapevine age, must turbidity, and yeast strain on the aroma of Vitis vinifera L. cv. Riesling wines. A recently developed, non-targeted SPME-GC-MS fingerprinting approach for wine volatiles was used. This approach includes the segmentation and mathematical transformation of chromatograms in combination with Parallel Factor Analysis (PARAFAC) and subsequent deconvolution of important chromatogram segments.

Fermentation derived sulfidic off-odors due to hydrogen sulfide (H2S) and low molecular weight thiols are commonly encountered in wine production and removed by Cu(II) fining. However, the mechanism underlying Cu(II) fining remains poorly understood, and generally results in increased Cu concentration that lead to deleterious reactions in finished wine. The present study describes a mechanistic investigation of the iron and copper mediated reaction of H2S, cysteine, 3-sulfanylhexan-1-ol, and 6-sulfanylhexan-1-ol with oxygen. The concentrations of H2S, thiols, oxygen, and acetaldehyde were monitored over time. It was found that Cu(II) was rapidly reduced by both H2S and thiols to Cu(I).

In modern viticulture, sustainability must be considered not only into the winery, but in the vineyard as well, being that with the most attentive interventions in order to protect the environment. In this context, the new “fungi resistant” varieties represent a valid option for reducing the negative environmental impact of agrochemicals used in viticulture, including those ones used in organic farming (given the copper accumulation into soils). Several application studies have demonstrated the enological validity of many resistant varieties, both in price and as a blend. Also, under the production point of view, the feasibility and economical sustainability of the new resistant varieties was verified. The aim of this work was to deepen the knowledge on the organoleptic characteristics of wines obtained from the Fleurtai and Soreli varieties and to compare them with the wine obtained from Tocai Friulano, the mother variety in the area destined for the production of the Lison Classico DOCG appellation. The purpose of the work is then to verify the possibility of introducing resistant varieties into the DOCG while maintaining the wine name of the appellation linked to the territory.

Wine oxidation phenomena during the different processes of winemaking, aging and storage are closely related to the presence of oxygen and to the wine’s capacity for consumption.