Effects of water and nitrogen uptake, and soil temperature, on vine development, berry ripening and wine quality of Cabernet-Sauvignon, Cabernet franc and Merlot (Saint-Emilion, 1997)

The growing demand for renewable energy and sustainable agricultural practices has highlighted the potential of agrivoltaics (Agri-PV) as a promising solution, particularly in the context of German viticulture.

Enological tannins are a diversified group of winemaking products that vary in several aspects such as chemical composition, botanical origin, and production method. In consideration of their richness in phenolic compounds, one of their main application in vinification is related to their antioxidant capacity, in particular their ability to consume oxygen during red wine maturation.

Ultrafiltration is a process that fractionates mixtures using semipermeable membranes, primarily on the basis of molecular weight. Depending on the nominal molecular weight cut-off (MWCO) specifications of the membrane, smaller molecules pass through the membrane into the ‘permeate’, while larger molecules are retained and concentrated in the ‘retentate’. This study investigated applications of ultrafiltration technology for enhanced wine quality and profitability. The key objective was to establish to what extent ultrafiltration could be used to manage phenolic compounds (associated with astringency or bitterness) and proteins (associated with haze formation) in white wine.

The presence of grape-derived heat unstable proteins can lead to haze formation in white wines [1], an instability prevented by removing these proteins by adding bentonite, a hydrated aluminum silicate that interacts electrostatically with wine proteins leading to their flocculation. Despite effective, using bentonite has several drawbacks as the costs associated with its use, the potential negative effects on wine quality, and its environmental impact, so that alternative solutions are needed.

ÂThe natural abundance of carbon stable isotopes has been reported to be related to water availability in grapevines quite widely. In the case of nitrogen, the natural abundance of its stable isotopes is mainly affected by the nature of the source of nitrogen (organic vs. inorganic) used by the plant, though the bibliography available for grapevine is very scarce.