Ripening of Vitis vinifera grapes varieties in São Joaquim, a new wine growing region, Southern Brazil

Constitue une appellation d’origine “la dénomination géographique d’un pays, d’une région ou d’une localité servant à désigner un produit qui en est originaire, et dont la qualité ou les caractères sont dus exclusivement ou essentiellement au milieu géographique, comprenant les facteurs naturels et les facteurs humains …”

Oxygen consumed by wine is used to oxidize sulfur dioxide and ethanol to form acetaldehyde wine oxygen consumption rate (OCR) was negatively correlated with the initial acetaldehyde level.

Fossil fuel combustion continues to drive increases in atmospheric carbon dioxide, consequently elevating the global annual mean temperature and specifically increasing the growing season temperatures in many of the world’s most important wine growing regions (IPCC 2014; Jones et al 2005). Grapes are sensitive to changes in growing season temperatures, and past models have shown a direct link between warming temperatures and earlier harvest dates (Cook and Wolkovich 2016). Globally, there have been shifts of 1-2 weeks for wine growing regions (Wolkovich et al 2017 and references within). The phenological shifts resulting from growing season temperature increases are documented internationally, and models predicting phenology using temperature are becoming more precise (Parker et al 2011).

Storage temperature and bottling parameters are among the most important factors, which influence the development of wine after bottling. It is well studied that higher storage temperatures speed up chemical reactions and results in faster wine aging [1,2]. It is also known that higher SO2 level and lower oxygen content provide better protection and longer shelf-life for the wine. At the same time, the mechanisms of chemical transformations of wine aromas during the aging process are not fully understood. In particular, how oxidation reactions contribute to the transformations of varietal aroma compounds.In the present study [3], we investigated the development of Riesling wine depending on a series of bottling conditions, which differed in the free SO2 level in wine (low—13 mg/L, medium—24 mg/L, high—36 mg/L), CO2 treatment of the headspace.

In a previous work1, it was suggested that the different contents in delphinidin and catechin of the grapes were determinant on the O2 consumption and Strecker aldehyde (SAs) accumulation rates. Higher delphinidin seemed to be related to a faster O2 consumption and a smaller SAs accumulation rate, and the opposite was observed regarding catechin.
In the present paper, these observations were fully corroborated by adding synthetic delphinidin to a wine model containing polyphenolic fractions (PFs) extracted from garnacha and synthetic catechin to a wine model containing PF extracted from tempranillo: The delphinin-containing garnacha model consumed O₂ significantly faster and accumulated significantly smaller amounts of SAs than the original garnacha model, and the catechin-containing tempranillo model, consumed O2 significantly slower and accumulated significantly higher amounts of SAs than the original tempranillo model.