IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Study of the evolution of tannins during wine aging by mass spectrometry monitoring of oxidation markers released after chemical depolymerization

Study of the evolution of tannins during wine aging by mass spectrometry monitoring of oxidation markers released after chemical depolymerization

Abstract

Among the many compounds in wine, condensed tannins play an important role in the organoleptic properties of the products; they are partly responsible for astringency, bitterness and also contribute to the color. This research work aims to study the oxidation state of these bio-heteropolymers which is an important lock in the analysis of processed products in order to better control their quality. Indeed, their identification remains at present a challenge because of the large heterogeneity of their degrees of polymerization (DP) based on 4 monomers (epicatechin, catechin, epigallocatechin, epicatechin-3-O-gallate) thus multiplying the number of oxidation products. Due to the difficulties of separation by liquid chromatography and detection by mass spectrometry of tannins with high DP1, tannins were analyzed by UHPLC-ESI-MS after chemical depolymerization. This pre-treatment of the samples allows the cleavage of the interflavanic bonds linking the constituent monomers of the tannins and gives access to the average DP and the proportions of the different monomers. However, in wines, many reactions take place from the beginning of the wine making process to its consumption. Within the tannin structures, the new covalent bonds created by oxidation are resistant to depolymerization conditions and oxidation markers (dimers and trimers) are then obtained. These structural modifications distort to a greater or lesser extent the estimation of the average DP depending on the oxidation state of the tannins. Faced with the complexity and the large number of oxidation products generated, over the last ten years a study conducted on model solutions has allowed the identification of more than one hundred oxidation markers2,3.
Thanks to the detection and identification of these oxidation markers, an in-depth study of the tannin fraction of wines has recently allowed us to understand theirs evolutions during ageing. Three Syrah wines (2018, 2014 and 2010 vintages) were analyzed. An accelerated oxidation of the 2018 vintage sample was also performed in order to evaluate the impact of this oxidation compared to the natural evolution and evaluate the ability of this oxidation to imitate natural evolution. The monitoring of 6 types of extension, extension/terminal and terminal markers at two oxidation levels was investigated. An evolution of the tannin oxidation state during ageing by the increase of the markers of the second oxidation level over the vintages was observed. In the 2018 oxidized wine sample, the first oxidation level markers are similar to the 2014 vintage but the second oxidation level markers are higher than other vintages, indicating a more advanced state of tannin oxidation. This study showed for the first time that it was possible to follow the oxidative evolution of wine tannins by monitoring some relevant dimeric tannin oxidation markers generated after chemical depolymerization.

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

Mouls Laetitia1, Deshaies Stacy1, Garcia François1, Suc Lucas1 and Saucier Cédric1

1SPO, Univ Montpellier, INRAE, Institut Agro

Contact the author

Keywords

Proanthocyanidin, Flavan-3-ol, oxidation marker, wine aging

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Isolation of indigenous yeast strains from the Purcari and Trifești wine centers in the Republic of Moldova and evaluation of their impact on the quality of dry red wines

In the conducted research, 30 yeast strains from red grape varieties were isolated from the Purcari wine center, and 28 yeast strains from red grape varieties were isolated from the Trifești wine center in the Republic of Moldova.
Read More

Contribution of grape and oak wood barrels to pyrrole content in wines – Influence of several cooperage parameters

Chardonnay is the world’s most planted white grape variety and has met a great commercial success for decades.

Read More

Effect of vigour and number of clusters on eonological parameters and metabolic profile of Cabernet Sauvignon red wines

Vegetative growth and yield are reported to affect grape and wine quality. They can be controlled through different techniques linked to vine management. The objective of this research was to determine the effect of vine vigour and number of clusters per vine on physicochemical composition and phenolic profile of red wines. The experiment was carried out during two vegetative cycles, with cv. Cabernet Sauvignon grafted onto Paulsen 1103. Three vine vigour were defined, according to shoot weight at previous harvests, being low, medium and high. Five treatments of number of clusters were used for each vigour, with 15, 22, 29, 36, and 45 clusters per vine. Grapes from all treatments were harvested in the same day from Brix and total acidity criteria. Thirty days after bottling, classical analyzes and phenolic compounds were performed. As results, different responses were obtained from each vintage. In 2020, a dry season from veraison to harvest, grapes and wines obtained from low vigour treatment and 45 clusters per vine was the highest in sugar and alcohol content respectively, while grapes and wines from high vigour and 15 clusters presented the lowest sugar and alcohol content. Total anthocyanins were higher in treatment with low vigour and 15 clusters, while the lowest amounts were found in low vigour with 45 clusters, as well as medium and high vigour with 36 clusters per vine. Total tannins were higher in high vigour with 22 clusters and medium vigour with 29 clusters, while were lower in low vigour with 36 clusters. In 2021, a wet season at harvest, responses were different, and great variations were observed between treatments. As conclusions, yield and vine vigour had strong influence on grape and wine quality, promoting different enological potentials on which can be indicated/used for aging strategies of red and even rosé wines.

Read More

EXPLORING THE METABOLIC AND PHENOTYPIC DIVERSITY OF INDIGENOUS YEASTS ISOLATED FROM GREEK WINE

Climate change leads to even more hostile and stressful for the wine microorganism conditions and consequently issues with fermentation rate progression and off-character formation are frequently observed. The objective of the current research was to classify a great collection of yeast isolates from Greek wines based on their technological properties with oenological interest. Towards this direction, fourteen spontaneously fermented wines from different regions of Greece were collected for further yeast typing. The yeast isolates were subjected in molecular analyses and identification at species level.

Read More

Deficit irrigation and mechanical canopy management affect berry and wine phenolic and aroma composition of Syrah in Central California

Labor shortage is one of the most crucial issues in current viticulture. Mechanized approaches are helpful in reducing production costs and increasing vineyard efficiency but their effect on grapes and wines needs evaluation. This work assess the results of combined mechanical pruning and shoot thinning with deficit irrigation strategies to reduce management costs but not quality of production.

Read More