Antifungal and Laccase-Suppressing Activity of Phenolic Compounds and Their Oxidation Products on Grey Mold-Fungus Botrytis cinerea

It is common to find tanks in the winery with wine below their capacity due to wine transfers between tanks of different capacities or the interruption of operations for periods of a few days. This situation implies the existence of an ullage space in the tank with prolonged contact with the wine causing its absorption/oxidation. Oxygen uptake from the air headspace over the wine due to differences in the partial pressure of O2 can be rapid, up to 1.5 mL of O2 per liter of wine in one hour and 100 cm2 of surface area1 and up to saturation after 4 hours.

Two of the most harmful microbial metabolites for human health that can be present in wines and either fermented or raw foods are biogenic amines (BA) and ochratoxine A (OTA). Winemakers are aware of the need to avoid their presence in wine by using different strategies, one of them is the use of enzymes. Some recombinant laccases have been characterized and revealed as potential tools to degrade these toxic compounds in wine[1], specifically biogenic amines[2].

Proteins constitute one of the three main components of grape juice and white wine, phenolic compounds and polysaccharides being the others. A specific group of the total grape-derived proteins resists degradation or adsorption during the winemaking process and remains in finished wine if not removed by the commonplace commercial practice of bentonite fining. While bentonite is effective in removing the problematic proteins, it is claimed to adversely affect the quality of the treated wine under certain conditions, through the removal of colour, flavor and texture compounds. A number of studies have indicated that different protein fractions require distinct bentonite concentrations for protein removal and consequent heat stabilization.

Aims: Some of the most direct effects of climate variability on grapevines are the changes in the onset and timing of phenological events and in the length of the growing season, which may affect grape quality. The aim of this research was to analyze the projected changes in vine phenology and on grape composition of the Tempranillo variety in Rioja DOCa under different climate change scenarios.

This study was conducted on soil-climate-plant relations (terroir) and their impact on grape composition and wine quality in the canton of Vaud by Agroscope Changins-Wädenswil ACW