WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 3 - WAC - Posters 9 Nucleophilic fraction to estimate the antioxidant activity of inactivated yeast derivates

Nucleophilic fraction to estimate the antioxidant activity of inactivated yeast derivates

Abstract

Oxidation in wine is mostly related to the Michael addition of nucleophiles on two quinones formed from the oxidation of ortho-diphenols. In wine this mechanism is responsible for the increase of the yellow hue and aroma loss. Glutathione exerts its antioxidant activity throughout its competitive addition onto quinones, but many other compounds can have the same behavior: sulfanyl compounds, amino acids, etc. Addition of yeast derivates during the winemaking process can increase the level of those nucleophilic compounds and then confer to the wine a higher resistance against chemical oxidation. In order to evaluate the antioxidant efficiency of yeast derivatives the measurement of radical scavenging activity was firstly applied in model wine like conditions. All tested YDs could reduce the DPPH radical, with yeast derivatives enriched in glutathione presenting the highest antiradical capacity compared to those without glutathione enrichment. To estimate the impact of the glutathione concentration on the DPPH results, its concentration was measured on the different solutions. However, there was no clear relationship between the concentration of native glutathione and the anti-radical activity of the YD (spearman correlation ρ = 0.46, p-value > 0.3) despite the known antiradical activity of glutathione. To go beyond the DPPH method, which does not provide any molecular information related to the antioxidant activity of inactivated yeast derivatives, we developed the measurement of inactivated yeast derivatives’ nucleophiles through the evaluation of the specificity and the kinetic of the competitive addition of nucleophilic compounds on the stable quinone 4-methylcatechol. The soluble part of yeast derivatives dissolved in a wine-like a model solution was added to this quinone and thanks to the LC-MS characterization of formed adducts, we could extract this nucleophilic fraction. The pool of 52 nucleophiles other than glutathione enabled to cluster the yeast derivatives according to their initial nucleophilic content and thus their potential antioxidant activity. The DPPH assay revealed the failure of the glutathione concentration to explain the scavenging activity of yeast derivatives soluble fractions. However, the derivatization procedure highlighted the potential of nucleophiles not considered until now to better characterize the antiradical activity of yeast derivatives soluble fractions. This study showed the major importance to consider the global nucleophilic fraction for a better assessment of the antioxidant potential of yeast derivative soluble fractions and highlights the potential of this approach for the characterization of oenological additives.

DOI:

Publication date: June 27, 2022

Issue: WAC 2022

Type: Article

Authors

Rémi Schneider, Régis Gougeon, Maria Nikolantonaki

Presenting author

Rémi Schneider – Oenobrands, Montpellier, France

Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, Institut Universitaire de la Vigne et du Vin – Jules Guyot, F-21000 Dijon, France, Florian Bahut DIVVA (Développement Innovation Vigne Vin Aliments) Platform/PAM UMR, IUVV, Rue Claude Ladrey, BP 27877, CEDEX, 21078 Dijon, France, Annabelle Cottet Oenobrands, Montpellier, France

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

Arsenic in soil, leaves, grapes and wines

The presence of arsenic in food and beverages creates concern because of the toxicity of this element, classified as carcinogenic in humans. The arsenic concentration in soil, vine leaves and berries

Effects of the biodynamic preparations 500 and 501 on vine and berry physiology, pedology and the soil microbiome

In the pursuit of increasing sustainability, climate change resiliency and independence of synthetic pesticides in agriculture, the interest of consumers and producers in organic and biodynamic farming is steadily increasing. This is in particular the case for the vitivinicultural industry in Europe, where more and more producers are converting from organic to biodynamic farming. However, clear scientific evidence showing that biodynamic farming improves vine physiology, vine stress resilience, berry or wine quality, or is more sustainable for the environment is still lacking although this issue has been addressed by several research teams worldwide.

Approaches to the classification of wine aroma aging potential. Applications to the case of Valpolicella red wines

Unlike most of other foods, wine sensory quality is thought to reach a peak after an aging period. In the case of the Valpolicella red wines

Grapevine varietal diversity as mitigation tool for climate change: Agronomic and oenologic potential of 14 foreign varieties grown in Languedoc region (France)

Climate change effects in Languedoc include an expected rise in temperatures, increased evapotranspiration as well as more severe and frequent climatic hazards, such as frost, drought periods and heat waves. For winegrowers theses phenomena impact both yield and quality, resulting in more frequent unbalanced wines. Research on identified mitigation tools for vineyard management is necessary to improve resilience of grapevine agrosystems. Varietal assortment is one of them. This study focuses on agronomic and oenologic potential of 14 foreign varieties grown in Languedoc French region. Fourteen grapevine varieties were monitored during 2021 from June until harvest on eight different sites, some of which occurring on more than one site adding up to 21 different modalities: 7 white varieties Alvarinho B, Assyrtiko B (2), Malvasia Istriana B, Parellada B, Verdejo B, Verdelho B, Xarello B, and 7 black varieties Saperavi N (2), Touriga nacional N, Baga N, Aleatico N, Montepulciano N (2), Primitivo N (3), Calabrese N (3). Varietals were compared through the following parameters: phenology was assessed by using the information collected in the Database Network of French Vine Conservatories (INRAE-SupAgro-IFV, 2005-2015). The number of inflorescences for shoots from secondary buds and bourillons and suckers were observed to assess post-bud break frost tolerance potential. Grapevine water status was studied through stem water potential measurement, observation of foliage symptoms of drought, and 𝛿13C on must. Frequencies and intensities of downy mildew, powdery mildew, and black rot attacks were estimated before harvest on leaves and clusters and botrytis at harvest to assess disease susceptibilities. Berry composition was monitored from end of veraison until harvest. Yield and mean bunch weight were also calculated. Varieties were then ranked on a 1-4 scale for each parameter and compared through PCA. Forty two stations of the Mediterranean basin were compared by PCA with the Multicriteria Climatic Classification indicators in order to confront the collected information during 2021 campaign to the hypothesis that plants coming from dry and hot regions are genetically adapted to such climatic conditions.

Elicitors application in two maturation stages of Vitis vinifera L. cv Monastrell: changes on the skin cell walls

AIM: In a recent study, it was determined that the mid-ripening period is the most suitable for the application of methyl jasmonate (MeJ), benzothiadiazole BTH and MeJ+BTH on Monastrell grapes, to favor maximum accumulation of phenolic compounds at the time of harvest. However, the increase in the anthocyanin content of