The influence of different fertiliser applications and canopy management practices on the potassium content and pH of juice and wine of Vitis vinifera L. cvs. Cabernet-Sauvignon and Cabernet franc

Commercial oenological tannins (TECs) are widely used in the wine industry. TECs are rich in condensed tannins, hydrolyzable tannins or a mixture of both. Wine grapes are a important source of proanthocyanidins or condensed tannins while oak wood possess a high concentration of hydrolyzable tannins (Obreque-Slier et al., 2009). TECs contribute with the antioxidant capacity of wine, catalyze oxide-reduction reactions and participate in the removal of sulfur compounds and metals.

Monferrato is a sub region of Piedmont featuring an endless series of hills which have been moulded through the centuries by laborious farming. Vineyards have always been the protagonists of Monferrato landscape. Asti vineyards have been well-known since Roman times and Pliny the Elder mentions them.

Wine fraud, encompassing counterfeiting and adulteration, poses a significant threat to the wine industry, resulting in annual losses totalling billions of dollars.

Pilzwiderstandsfähige (PIWI) are disease resistant Vitis vinifera interspecific hybrid varieties that are receiving increasing attention for ability to ripen in cool climates and their resistance to grapevine fungal diseases. Wines produced from these varieties have not been characterized, especially regarding their macromolecular composition. This study characterised and quantified colloid-forming molecules (proteins, polysaccharides and phenolics) of red PIWI wines produced in the UK. METHODS: In 2019 6 wines were made from the PIWI varieties Rondo, Cabernet Jura, Cabernet Cortis, Cabernet Noir, Regent and Cabertin grown at the Plumpton Rock Lodge Vineyard in Sussex (UK) and harvested at similar level of maturity (TSS, pH and TA). All juice was chaptalized to the same potential alcohol of 12%. Small scale winemaking (1L) was performed in quadruplicate using Bodum® coffee plungers to manage maceration [1]. Residual sugar content, pH, and titratable acidity were monitored during fermentation. For finished wines, the protein and polysaccharide content was measured by HPLC-SEC [2], while the total phenolic content was assessed using the Folin-Ciocalteau method [3]. The protein profile of the wines was further investigated by SDS-PAGE [4]. RESULTS: Fermentations (n=24) were all carried out to completion within 8 days.

The cultivation of grapes, can be accomplished with the use of different systems and practices of agricultural management, the choice of the system to be followed in the vineyard, depends on the conditions of available resources, these being: natural, economic, social, cultural and territorial. As well, it is relevant to know the characteristics of the soil of the vineyard. In the last decade, has been recurrent use of agricultural practices which date back to milinares traditions, with the aim of promoting a recovery of soil and lead the management of cultivation with less damage to the ecosystem. The study here, aimed to quantify the environmental impacts caused in the use of nutrients in conventional tillage and of grapes in the biodynamic agricultural properties in the state of Rio Grande do Sul- Brazil.