Macrowine 2021
IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Grapevine diversity and viticultural practices for sustainable grape growing 9 Evaluation of glutathione content in four white varieties in the d.o. Ca. Rioja (Spain)

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

Abstract

AIM: Glutathione is a tripeptide that is mainly found in reduced form in grapes. It generates during the maturation of the grape, increasing significantly after veraison [1]. It plays a relevant role in the prevention of oxidative processes due to its high antioxidant activity. Its content in the grape is influenced by many factors (variety, vintage, cultural practices, nitrogen nutrition …) [2]. In musts and wines, it undergoes modifications due to oxygen exposure, tyrosinase activity, maceration time, pressing, yeast strain…[3]. The aim of this work was to evaluate the content of glutathione in the grape of four white varieties: Tempranillo Blanco, Maturana Blanca, Garnacha Blanca and Viura.

METHODS: The study was carried out during three seasons (2017, 2018 and 2019) in a vineyard located in the D.O.Ca. Rioja (Spain). On the other hand, the influence of different vineyard locations on the content of this compound in the indicated varieties was also analyzed. Glutathione determination was carried out by HPLC by automatic derivatization in precolumn with OPA. The previous extraction in the grape was carried out with HCl/EDTA [4].

RESULTS: The results obtained showed important varietal differences in the glutathione content of the grape in the white varieties studied. The highest concentration was obtained in the Tempranillo Blanco variety, although without significant differences in comparison to Viura, while the lowest levels corresponded to Maturana Blanca and Garnacha Blanca. Also, the characteristics of the vintage also influenced its concentration, although the varietal differences were maintained. The location of the vineyard showed a variable effect depending on the vinifera, and the characteristics of the vintage in the case of Tempranillo Blanco.

CONCLUSIONS

These results confirm that the variety is one of the most influential factors in the glutathione content in grapes. Tempranillo Blanco has high levels of this compound, which can help preserve the quality of your wines.

DOI:

Publication date: September 2, 2021

Issue: Macrowine 2021

Type: Article

Authors

Juana Martinez

Instituto De Ciencias De La Vid Y Del Vino (Gobierno De La Rioja, Csic, Universidad De La Rioja),Laura, Alti, Instituto De Ciencias De La Vid Y Del Vino (Gobierno De La Rioja, Csic, Universidad De La Rioja)  Sara, Garcia, Instituto De Ciencias De La Vid Y Del Vino (Gobierno De La Rioja, Csic, Universidad De La Rioja) Elisa, Baroja, Instituto De Ciencias De La Vid Y Del Vino (Gobierno De La Rioja, Csic, Universidad De La Rioja)

Contact the author

Keywords

glutathione, grape, white varieties, location, season

Citation

Related articles…

CHARACTERIZATION OF THE AROMA PROFILE OF COMMERCIAL PROSECCO SPARKLING WINES

The typicality of a wine, as well as its aromatic identity, are attributes that are highly sought after and requested by the current market. It is therefore of considerable technological interest to investigate the aromatic aspects of specific wines and to identify the odorous substances involved.In this thesis work, the characterization of the aromatic composition of Prosecco wines available on the market with a price range between 7 and 13 euros was carried out. These wines came from three different areas of origin such as Valdobbiadene, Asolo and Treviso.

Mechanization of pre-flowering leaf removal under the temperate-climate conditions of Switzerland

Grapevine leaf removal (LR) in the cluster area is typically done between fruit set and cluster closure to create an unfavorable microclimate for fungal diseases, such as Botrytis cinerea and powdery mildew. Grape growers are now turning their attention to pre-flowering LR, which has additional benefits under certain conditions. When applied before flowering, LR strongly affects fruit set and thus the number of berries per cluster. It is therefore a good yield control tool, replacing time-consuming manual cluster thinning (Poni et al. 2006). It also improves berry structure, that is, skin thickness, skin-to-pulp ratio, and berry composition (total soluble solids, titratable acidity, and polyphenols) (Palliotti et al. 2012; Komm and Moyer 2015). By exacerbating competition for assimilates between reproductive and vegetative organs, pre-flowering LR also poses some risks. Excessive yield loss at the same year’s harvest due to a too low fruit set rate is the main concern: intensive pre-flowering LR (100% of the cluster area) can induce up to 50% yield loss in potted vines (Poni et al. 2005). Other parameters, such as cool climatic conditions during flowering, also affect fruit set rate and make it difficult to predict potential yield at harvest. Repeated and overly intensive preflowering LR can have repercussions over time and induce a decline in bud fruiting and plant vigor (Risco et al. 2014).

Characterization of a strain of Lachancea thermotolerans, microorganism of choice when facing the climatic challenges of the wine sector

Current climatic challenges in the wine sector require innovative solutions to maintain the quality of wines while adapting oenological practices to changing conditions. This article presents the detailed study of a lachancea thermotolerans strain on matrices typical of the French mediterranean area.

Effect of topography on vine evapotranspiration and water status in hillside vineyards

Many winegrape regions have hillside vineyards, where vine water use is affected by vine age, density and health, canopy size, row orientation, irrigation practices

Measurements of the oxygen dissolved in white wines elaborated in barrels without to open the bung of the barrels

Bases on oxoluminescence, we have developed an innovative device for measuring dissolved oxygen in wines in barrels without opening the bung. This system is directly inserted into the wood during the barrel elaboration and can be positioned at different locations of the barrel (the head, the hull …). During two successive vintages we have used this device notably to follow the oxygen dissolved of whites wines elaborated in barrels. This allowed us initially to monitor the oxygen levels of the harvest to bottling the whole elaboration process in barrels of white wines without using techniques of measurement suitable to modify the real values in wines (opening the bung to plunge an oximeter).