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…

Understanding the expression of gene families involved in anthocyanin biosynthesis during berry ripening: Tannat as a case study

The quality of wine is assessed, among other things, by its color, which is mainly due to its anthocyanin content. These pigments are polyphenols that give red, purple and blue hues depending on the relative proportion of anthocyanins produced by the action of flavonoid 3’5′ hydroxylase (delphinidin-3-glucoside, petunidin-3-glucoside, malvidin-3-glucoside) or flavonoid 3′ hydroxylase (cyanidin-3-glucoside, peonidin-3-glucoside). To study the genes involved in this biosynthetic pathway, we focused on Vitis vinifera cv. Tannat, known for producing wines with higher anthocyanin content and darker purple color compared to most red grape varieties. In this work, we have performed RNA-Seq analysis of skins during berry development, taking green and red berries at 50% veraison as separate samples, as an experimental strategy to focus on the differential expression of genes of interest.
Read More

From vineyard to bottle. Rationalizing grape compositional drivers of the expression of “Amarone della Valpolicella” terroir

Valpolicella is a famous Italian wine-producing region. One of its main characteristic is the intensive use of grapes that are submitted to post-harvest withering. This is rather unique in the context of red wine, especially for the production of a dry red wine such as Amarone. Amarone wines produced in Valpolicella different geographic origin are anecdotally believed to be aromatically different, although there is no systematic study addressing the chemical bases of such diversity. Aroma is the product of a biochemical and technological series of steps, resulting from the contribution of different volatile molecules deriving from grapes, fermentations, and reactions linked to aging, as well as one of the most important features in the expression of the geographic identity and sensory uniqueness of a wine.

Read More

Definition and planning of viticultural landscapes case study in the “Côtes du Rhône Gardoises”

Les préoccupations actuelles autour des paysages viticoles vont au-delà des clichés promotionnels développés par les stratégies marketing. En effet, les paysages sont aujourd’hui au cœur d’une demande sociale croissante qui se traduit par différentes lois (la loi paysage de 1993, le paysage reconnu comme patrimoine commun de la nation par la loi n°95-101, la création du Conseil national du paysage par arrêté du 8/12/2000).

Read More

An intra-block study of bunch zone air temperature and its impact on berry and wine attributes

Temperature is a key environmental factor affecting grape primary and secondary metabolites. Even if several mesoscale studies have already been conducted on temperature
especially within a Protected Designation of Origin area, few data are available at an intra-block scale. The present study aimed at i) assessing the variability in bunch zone air temperature within a single vineyard block and the temporal stability of temperature spatial patterns, ii) understanding temperature drivers and
iii) identifying the impact of temperature on grape berry attributes.

Read More

Agronomic behavior of three grape varieties in different planting density and irrigation treatments

In the O Ribeiro Denomination of Origin, there is a winemaking tradition of growing vines under a high-density plantation framework (8,920 vines/ha) and maintaining its vegetative cycle under rainfed conditions.
Currently, viticulture is advancing to plantation frames in which the density is considered medium (5,555 vines/ha), thus allowing mechanized work to be carried out for vineyard management operations. Although, the application of irrigation applied proportionally to the needs of the vegetative cycle of the vine, is a factor that increasingly helps a good development of the vine compared to the summer period, with increasingly uncertain weather forecasts.

Read More