WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 3 - WAC - Oral 9 What happens with the glutathione during winemaking and the storage of the wine?

What happens with the glutathione during winemaking and the storage of the wine?

Abstract

We tried to give a part of the answer to this question by monitoring glutathione during winemaking and storage. The novelty of our approach is to quantify simultaneously the three known forms of glutathione: free glutathione (GSH), oxidized form (GSSG) and glutathione-S-sulfonate (GSSO3H). This last molecule was reported first in wine by Arapatsis et al. (2016), who described the reaction between SO2 and GSSG resulting GSH and GSSO3H. Theoretically, GSH can further react with SO2, but this reaction is slow. This results obtained in model wine was now proved in grape juice, by measuring the kinetic of the reaction after the addition of SO2. For this purpose a LC-MS/MS analysis method was developed, which allows for the first time the quantification of GSSO3H beside of GSH and GSSG in the wine. 

The analyses of samples taken in the different moment of winemaking shows that in the must only GSH and GSSG are present. GSSO3H appears after the addition of SO2 at the end of the alcoholic fermentation. It appears also to be the dominant form of glutathione in SO2 containing wines after 3 months storage. The analysis of a hundred of wines showed a correlation between the relative concentration of GSSO3H and the total SO2 level of the wine. Temperature also effects the reaction rate. Grape variety does not seem to influence the formation of GSSO3H. 

We could conclude that SO2 contribute to release active GSH from the GSSG and so extend the protection potential against oxidation during the first months of storage. It remains the questions: Does GSSO3H have any antioxidant activity? Further investigation would be needed to address this question. However, in the meantime, its quantification is important in the wine to avoid underestimating the glutathione content.

DOI:

Publication date: June 14, 2022

Issue: WAC 2022

Type: Article

Authors

Ágnes Dienes-Nagy, Frédéric Vuichard, Sandrine Belcher, Marie Blackford, Johannes Rösti, Fabrice Lorenzini

Presenting author

Ágnes Dienes-Nagy – Agroscope, 1260 Nyon, Switzerland

Agroscope, 1260 Nyon, Switzerland | Agroscope, 1260 Nyon, Switzerland | Agroscope, 1260 Nyon, Switzerland| Agroscope, 1260 Nyon, Switzerland | Agroscope, 1260 Nyon, Switzerland 

Contact the author

Keywords

glutathione, wine, glutathione-S-sulfonate, LC-MS/MS

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

Longevity and moderate wine consumption – can guidelines provide practical advice?

Conflicting messages about the consumption of alcoholic beverages – including wine – continue to dominate the media, causing increasing uncertainty among consumers and health professionals.

Implications of the respect of pruning principles on grapevine development

After some decades sunk into oblivion, pruning has recently recovered the focus of grape growers and viticulturists worldwide. Attention is now being paid to the respect the sap flow continuity and to pruning wounds, as they may affect the general performance and longevity of the plant. The longevity and profitability are strongly affected by the increasing incidence of grapevine wood diseases (GWD), intensified by the omission of good pruning practices and leading to an increasingly aggressive pruning. The purpose of this study is to provide an objective evaluation of the short- and mid-term implications of different pruning practices that differ in the degree of observation several of pruning principles.

Copper contamination in vineyard soils of Bordeaux: spatial risk assessment for the replanting of vines and crops

Copper (Cu) is widely and historically used in viticulture as a fungicide against mildew. Cu has a strong affinity for soil organic matter and accumulates in topsoil horizons. Thus, Cu may negatively affect soil organisms and plants, consequently reducing soil fertility and productivity. The Bordeaux vineyards have the largest vineyard surfaces (26%) within French controlled appellation and a great proportion of French wine production (around 5 million hl per year). Considering the local context of vineyard surfaces decreasing (vine uprooting) and possible new crop plantation, the issue of Cu potential toxicity rises. Therefore, the aims of this work are firstly to evaluate the Cu contamination in vineyard soils of Bordeaux, secondly to produce a risk assessment map for new vine or crop plantation. We used soil analyses from several local studies to build a database with 4496 soil horizon samples. The database was enhanced by means of pedotransfer functions in order to estimate the bioaccessible (EDTA-extractable) Cu in soils of samples without measurements. From this database, 1797 georeferenced samples with CuEDTA concentrations in the topsoil (0-50 cm depth) were used for kriging interpolation in order to produce the spatial distribution map of CuEDTA in vineyard soils. Then, the spatial distribution of Cu was crossed with vine uprooting surfaces and municipality boundaries. CuEDTAconcentrations ranged from 0.52 to 459 mg/kg and showed clear anomalies. Our results from spatial analysis showed that almost 50% of vineyard soil surfaces have CuEDTA concentrations higher than 30 mg/kg (moderate risk for new plantation) and 20% with concentrations higher than 50 mg/kg (high risk for new plantation). A decision-support map based on municipalities was realised to provide a simple tool to stakeholders concerned by land use management.

Validating a portable ad-hoc fluorescence spectrometer for monitoring phenolic compounds during wine fermentation

Phenolic compounds are fundamental to wine quality, influencing its colour, mouthfeel, stability, and ageing
potential [1]. Their extraction and evolution during fermentation plays a crucial role in determining the final sensory
attributes and requires careful monitoring to guide winemaking decisions.

Simplifying the measurement of different forms of cu in wines and strategies for efficient removal

Copper (Cu) is known to substantially impact wine stability through oxidative, reductive or colloidal phenomena. Recent work has shown that Cu exists predominantly in a sulfide-bound form, which may act as a potential source of sulfidic off-odours in wine and hence contribute to reductive flavours