The effect of rootstock on water relations and gas exchange of Vitis vinifera cv. Xinomavro

Aims: In previous work, five indigenous Pichia kluyveri strains, GS1-1, FS-2-7, HS-2-1, C730 and C732, were isolated and selected from spontaneous fermented wines from Ningxia and Gansu. The aims of this study were to 1) evaluate resistance of these strains to environmental stressors that may restrict their growth and the progress of alcoholic fermentation; 2) Investigate their fermentation dynamics; 3) Characterise aroma profiles of Cabernet Sauvignon wines made from mixed cultures of P. kluyveri and Saccharomyces cerevisiae.

Molecular markers of wine oxydation, such as sotolon or Strecker’s aldehydes that induce respectively nut or curry and boiled vegetables or wilted rose odors, can be percieved as a default by consumers. These volatile compounds are especially formed during the premature aging of wine, but it is likely that several contributing compounds are still unknown as is their combined contribution. This study was carried out to identify the markers of oxydation in Chardonnay wine by Gas Chromatography Olfactometry (GC-O) and to study the impact of these markers on the complex wine aromatic buffer using the Olfactoscan approach.A Chardonnay wine (2018-vintage), taken after malolactic fermentation without sulphites addition, was submitted to an artificial oxidation to simulate more or less prononced premature oxidation. Volatile compounds were extracted by Solid-Phase Extraction (SPE) and analysed by GC-O with a panel of 13 trained subjects. The same extract was also submitted to a second analysis based on the Olfactoscan technique, which allowed to evaluate the impact of each volatile compounds on the complex aromatic buffer of a non-oxidized wine delivered as background odor. Preliminary results revealed three types of behavior. On the one hand, several odor zones appeared only with the background odour, suggesting a synergy effect induced by the compounds in the aromatic buffer. Conversely, odor-active compounds could not be perceived within the background odor suggesting a masking effect. Finally several compounds were found to contribute as key odorants for wine oxydation once mixed with the aromatic buffer. These compounds are still to be identified using complementary techniques.

Oxidative stability is a critical factor in maintaining wine quality during its shelf-life. SO₂ is commonly added to wine due to its strong antioxidant activity, although there is a general push to reduce SO₂ use in vinification.

Climate change is having a profound effect on viticulture by altering the conditions under which vines grow, leading to increased water stress and earlier harvests, which in turn affect the quality and character of wines [1].

I territori della DOC “Terre dell’Alta Val d’Agri”, a Sud della regione Basilicata, si caratterizzano per una elevata biodiversità autoctona autoselezionatesi su ambienti ecologicamente ben definiti,