Effects of different antioxidant strategies on the phenolic evolution during the course of a white winemaking process

Context and purpose of the study. Reducing pesticide use such as glyphosate, is a key challenge to support sustainability of viticulture systems and resilience of vineyard.

One of the main aspects of Climate Change is the increase of temperatures during summer and grape maturity period. Physiological processes are influenced by these high temperatures and result in grapes with higher sugar concentration, less acidity and less anthocyanin content among other quality changes. One strategy to deal with the climate change effects is the implementation of late winter pruning to alter the effect of high temperatures during key periods by delays in maturity time.

In the Champagne vineyards, spring frosts are the cause of significant variations in the volume of the harvest which are very penalizing for the trade. This variability is reflected both in time (years without frost alternating with years with severe frosts) and in space. Certain sectors of the vineyard are in fact statistically more susceptible to frost than others, but each year no municipality can consider itself immune to this climatic accident. The objective of the study is precisely to analyze the spatial distribution of frost and to determine its main mechanisms, linked to the topography of the hillsides, their orientation but also to regional meteorological variables.

This study evaluated the physicochemical parameters of grape juices produced in the serra gaúcha from the 2019 and 2020 harvests. To do this, 43 juice samples were analyzed, and divided into four distinct categories: juices made exclusively from bordô grapes (sb), juices made from bordô and niágara grapes (sbn), juices combining bordô and isabel grapes, and juices made from cuts of several grape varieties.

Galloylated flavan-3-ols are a class of polyphenolic compounds present in various plants, including grape seeds. These compounds are formed through the condensation of flavan-3-ols, such as catechins, although the precise mechanism by which gallic acid is incorporated into the molecule remains unclear.