Evaluation of glutathione content in four white varieties in the d.o. Ca. Rioja (Spain)

In recent years, the increase in temperature and the changes in rainfall distribution caused by climate change are affecting vine and grape physiology and are consequently impacting wine composition and quality (Schultz, 2000; Jones et al., 2005).

Winegrowers must adapt more and more their viticultural practices in order to evolve toward a sustainable viticulture, to be competitive and to improve both the production methods and the quality and typicalness of wines. In this context, ‘Terroir’ studies in Loire Valley vineyards have allowed to build decision aid maps that can be used directly by growers to adjust their practices.

The microbial composition of the soil is an important factor to consider in viticulture, since its influence on the “terroir” and on the organoleptic properties of the wine have been demonstrated. Different agronomic techniques have the potential to modify the composition and functionality of the soil microbial community. Maintaining green covers is known to increase soil microbial diversity. The direct application of inoculum of beneficial microorganisms to the soil has also been used to increase their abundance. However, the environmental conditions of each site seem to have a determining weight in the result of these practices. In this study, we compared the effect on the microbial community of a cover crop with legumes in autumn and the inoculation of grapevines with commercial inoculum bases on Rhizophagus irregularis and Funeliformis mosseae in the previous spring. The study has been carried out in a vineyard in Binissalem, Mallorca, Spain. After applying the treatments, we will analyze the soil microbial communities using the data obtained from Illumina amplification of soil DNA from the 16S and ITS regions to analyze bacteria and fungi community, respectively. In addition, we will record the physicochemical characteristics of the soil at each sampling point. The result showed that agronomic management, in the short term, has less influence than soil characteristics on the composition of the soil microbiome. With these results, we can conclude that in a vineyard, agricultural techniques should focus on improving the characteristics of the soil to improve the biodiversity of the soil microbiota.

The abbreviation AOC designates, since 1905 in France, wines which characteristics and reputation are due to a proper “terroir”. The delimitation of such “terroirs” consists in a technical and statutory procedure which has developed by steps.

Oxidative stability is a critical factor in wine shelf-life. SO₂ is commonly added to wine due to its strong antioxidant activity, although there is a general push to reduce SO₂ use in vinification.