Comparison of the free radical-scavenging activity in infected oidium and sound dolcetto grape cultivar grown in a terroir of Central Italy

Noble rot sweet wines are reputed wines, traditionally elaborated according to a singular vinification process involving the harvesting of overripe grapes under the action of the ascomycete fungus Botrytis cinerea.

Heatwave events, defined as 2 or more days reaching ≥ 38 °C, are an increasingly frequent phenomenon threatening grape production worldwide. Heat stress has been shown to have negative consequences on grapevine physiology, leading to increased evaporative demand and intensified water stress. Due to heatwaves overlapping with important stages of grapevine reproductive development, spanning from berry set to the ripening stage, severe heat can potentially compromise yield and grape quality. The physiological response of grapevine to heat stress suggests a potential use of irrigation to mitigate heatwaves, however there is limited information regarding the irrigation amounts and timings needed for this purpose. Following up on a pivotal trial conducted between 2019 and 2022, in this study irrigation treatments with varying intensity and timing of application were refined to determine their potential mitigation of heat-associated damage to yield and fruit composition.

In Franconia, the northern part of Bavaria in Germany, climate change, visible in earlier bud break, advanced flowering and earlier grape maturity, leads to a decrease of traditionally cultivated early ripening aromatic white wine varieties as Mueller-Thurgau (30 % of the wine growing area) and Bacchus (12 %). With the predicted rise of temperature in all European wine regions the conditions for white wine grape varieties will decline and the grapes themselves will lose a part of their aromatic and fruity expression. Variety change towards the cultivation of later ripening white wine varieties is a very expensive and long-term process, and must be accompanied by special marketing efforts.

Grappa is the most important italian spirit and its production includes elements of history, tradition, and culture of the transalpine country. In accordance with EU laws, grappa is obtained from the fermentation and distillation of the pomace, eventually added with fermentation lees and water. Grappa is one of the richest fruit distillates in volatile compounds that confer to the product its characteristic flagrance. The aroma is largely due to the volatile compounds present in the raw materials, in particular alcohols, esters and carbonyl compounds formed during the alcoholic fermentation, but also to grape aromas such as terpenols and norisoprenoids, that confers grappa the distinctive floral scents.

A relatively small number of the many volatile substances of wine, often present at trace
concentrations, are considered as key volatile compounds. These compounds often exist in grapes
under poorly odoriferous or non volatile forms as aroma precursors.