New understanding on sulfites reactivity in wine

Ontario’s wine regions lie at the climatic margins of commercial viticulture owing to their cold winters and short cool growing season. The gradual warming of northern latitudes projected under a human-induced climate change scenario could bring mixed benefits to these wine regions.

Climate change increasingly leads to altered growing conditions in viticulture, such as heat stress, drought or high infection pressure favoring pathogen infection.

Phenolic compounds are important quality indicators in red wine. A large number of polyphenols play an important role in wine development, contributing to the colour and the sensory perception of the wines. Anthocyanins are the pigments responsible for the colour in young red wines while tannins are the principal contributors to the bitterness and the astringency of the wines. Wine polyphenols are considered more complex molecules than grape phenolics, due to the enormous number of chemical reactions which take place during the entire winemaking process and storage, forming more stable compounds.

The use of new fungus disease-tolerant grapevine varieties is a long-term and promising solution to reduce chemical input in viticulture. However, little is known about the effects of water deficit (WD) on the thiol aromatic potential of new varieties coming up from breeding programs. Varietal thiols such as 3-sulfanylhexan-ol (3SH), 4-methyl-4-sulfanylpentan-2-one (4MSP) and their derivatives are powerful aromatic compounds present in wines coming from odorless precursors in grapes, and could contribute to the wine typicity of such varieties.

Vineyard yield forecasting is a key issue for vintage scheduling and optimization of winemaking operations. High errors in yield forecasting can be found in the wine industry, mainly due to the high spatial variability in vineyards, strong dependency on historical yield data, insufficient use of agroclimatic data and inadequate sampling methods