Effect of ozone application for low-input postharvest dehydration of wine grapes 

The aromatic perception is one of the main factors that influence the
consumer when determining the wine’s quality and acceptance. Numerous factors (soil, climate,
winemaking style, cultivar) can influence the volatile compounds. Some of these compounds are released directly from the grape berries while others are formed during the fermentation and aging processes. However, little is known about the quality and aromatic formation of Syrah variety in the winter cycle cultivated in São Paulo.

White wines contain macromolecules such as proteins, phenolic compounds and polysaccharides. On a sensory
level, these compounds contribute to the ‘mouthfeel’ that differentiates the white wines worldwide [1].

Smoke impacts on wines are becoming a worldwide problem; the size and severity of wildfires increasing due to influences from changing climates.¹ For over a century, wines have been known to have a unique issue of absorbing chemical compounds derived from wildfire smoke wherein the flavor of the subsequent wine becomes ashy, rubbery, campfire-like, and smoky.² The economic impacts of a smoke-impacted wine can last for years depending on the grape varietal, costing Oregon and Washington states in the United States over a billion dollars from the 2020 wildfires, as an example.³ While years of research have indicated elevated concentrations of smoke-related compounds, such as guaiacol and syringol, in wines after smoke events, unfortunately, replicating the sensory experience using smoke-associated phenols has not had much success.⁴

Around the world, the alcohol content of wine has been steadily increasing; partly as a consequence of climate change, but also due to improvements in viticultural management practices and winemaking techniques [1,2]. Concurrently, market demand for wines with lower alcohol levels has increased as consumers seek to reduce alcohol intake for social and/or health reasons [3]. As such, there is increasing demand for both innovative methods that allow winemakers to produce ‘reduced alcohol wines’ (RAW) and a better understanding of the impact of such methods on the composition of RAW. This study therefore aimed to investigate compositional changes in two red wines resulting from partial alcohol removal following treatment by one such method, involving a combination of reverse osmosis and evaporative perstraction (RO-EP).

Extreme climatic events, such as prolonged drought followed by intense flooding, increasingly impact viticulture, affecting vine physiology, productivity, and grape composition.