Valorization of grapevine leaves: screening of polyphenol composition in 50 cultivars

The O2 uptake in the different winemaking processes is generally considered to be negative for the sensory characteristics of white and rosé wines. Wine racking is a critical point of O2 uptake, as the large surface area of the wine exposed during this operation and the inability to maintain an effective inert gas blanket over it.
The objective was to study O2 uptake during the racking of a model wine without using inert gases and to compare it with the purging of the destination tank with different inert gases.

Climate changes have important consequences in viticulture, heat waves accompanied by periods of drought are encountered more and more frequently. This study aims to evaluate the single and combined effect of water deficit and high temperatures on the thiol precursors biosynthesis in Sauvignon blanc grapes. For this purpose, a protocol has been developed for the cultivation of berries on a solid substrate. The berries, collected at three different times starting from veraison and grown in vitro, were subjected to 4 different treatments: control (C), water stress (WS), heat stress (HS), combined water and heat stress (WSHS). Water stress was simulated by adding abscisic acid to the culture medium, while different temperatures, respectively 25°C and 35°C, were managed with two illuminated climatic chambers.

The sustainability of viticulture in response to climate change has been addressed mainly considering agronomic impacts, such as water management and diseases, either separately or together.
In grapevines, there is strong evidence that different genotypes respond differently to biotic and abiotic stresses. A screening was conducted on various local cultivars in response to drought and Neofusicoum parvum infection aiming to evaluate their susceptibility to abiotic stress and resistance to fungal diseases.

The European wine industry is facing multiple challenges derived from climate change and the pressure of different fungal diseases that are compromising the production of traditional varieties. A sustainable alternative maybe the adoption of resistant varieties.
In this study, we have evaluated the enological potential of 9 resistant varieties (5 white and 4 red varieties) in La Rioja. Microvinifications were carried out with three biological replications. Oenological parameters were very diverse with acid content varying from 2.6 g/L to 6.6 g/L.

The wine closure industry is mainly divided into three categories: screw caps, synthetic closures, and cork-based closures. Among this latter, microagglomerated cork stoppers treated with supercritical CO2 are now widely used, especially to avoid cork taint contaminations[1]. They are designed with cork granules obtained from cork offcuts of the punching process during the natural cork stoppers production. A previous study[2] showed that these stoppers released fewer polyphenols in 12 % (v/v) hydroalcoholic solution than natural cork stoppers.