Antociani ed acidi cinnamici per la caratterizzazione di vitigni in zone diverse della Toscana

Mannoproteins are macromolecules found on the surface of yeast cells, composed of hyperbranched polysaccharide negatively charged chains by mannosyl-phosphate groups, fixed to a protein core. during the alcoholic fermentation and aging on lees, these mannoproteins are released from the yeast cell wall and become the main yeast-sourced polysaccharide in wine. due to their techno-functional properties, commercial preparations of mannoproteins can be used as additives to better assure tartaric and protein stability.

Anthocyanin accumulation and extractability were studied in Tannat, Cabernet Sauvignon and Merlot grapes produced in the south of Uruguay in two consecutive seasons. Typical cultivation situations employed in the region for each variety were considered. A follow-up was carried out, considering 60 plants per vineyard, and the harvest was determined according to the technological indices of maturity. Samples of grapes were taken in duplicate in each vineyard periodically along grape maturation. The basic composition, polyphenolic potential and anthocyanin extractability were determined. Also, half of grapes were frozen and later peeled; skin extractions over 24 hs with a solution of 12% ethanol and pH 3.2 were carried out. The anthocyanin contents of the extracts obtained were determined by HPLC-DAD. The levels of anthocyanins reached the highest values before technological maturity. Anthocyanin extractability had a decrease during grape maturation.

The dynamic evolution of some bioclimatic indices largely used to define the vocation of areas to grape growing was assessed over 43 years (1965-2007) in four sites of the Abruzzo Region (Central Italy).

Agriculture worldwide is threatened by climate change. In particular, declining water resource availability combined with increasing water demand is a key challenge in many rainfed areas, where irrigation appears to be a straightforward adaptation option. In this context, assessing the impacts of irrigation adoption on farm yields and incomes is a necessary step to reflect on the impact of both ex-post and ex-ante policies.

Non-saccharomyces yeasts gained an increased interest in winemaking during the last decades, due to their ability to produce relevant amounts of polysaccharides. Moreover, a significant release of glutathione into the wine during fermentation was also observed with these strains, as well as an improvement of color stability and wine aroma profile. Valuable results have been obtained by hanseniaspora spp. concerning the release of polysaccharides and the production of acetic esters, mainly during fermentation.