Macrowine 2021
IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Chemical diversity of 'special' wine styles: fortified wines, passito style, botrytized and ice wines, orange wines, sparkling wines 9 Identification and quantification of molecular ellagitannins in cognac eaux-de-vie by a mass spectrometry method: barrel toasting and aging impact

Identification and quantification of molecular ellagitannins in cognac eaux-de-vie by a mass spectrometry method: barrel toasting and aging impact

Abstract

AIM: Ellagitannins are the main oak wood phenolic compounds that contribute to wine and spirits organoleptic quality (color, astringency, bitterness)(1-3). Given the lack of knowledge regarding their composition and evolution in spirits, the objectives were to follow their extraction kinetic in Cognac “eaux-de-vie” matured in barrel representing different toasting and to observe their evolution and structural modifications during aging.

METHODS: Eight different toasting levels were used for studying the impact of the toasting on ellagitannins composition. Two verticals (1978-2018) of “eaux-de-vie” samples coming from two terroirs were analyzed in order to observe ellagitannins evolution during aging. The above analyses were conducted using HPLC-Triple Quadrupole mass spectrometer (4) and the unknown compounds were identified by UPLC-Q-TOF, purified by preparative HPLC prior to 1D/2D-NMR analysis.

RESULTS: A general trend between the toasting levels and the individual ellagitannins content and composition was observed. Indeed “Eau-de-vie” aged in light toasted barrel has 40% higher castalagin content than in high toasting. During spirit aging, native ellagitannins content decreases over time. After two years, only castalagin remains quantifiable, suggesting that they undergo transformations leading to the formation of new compounds. Among them, whisky tannin B and A ([M-H]- ion peak at m/z 977.0896 and m/z 675.0834 respectively), resulting from the ethanol/castalagin or castalin reaction as well as some ellagitannin oxidation products like dehydrocastalagin and dehydroroburin D were identified for the first time in Cognac “eaux-de-vie” samples. The kinetic of the above compounds is in progress and the influence of both aging and barrel toasting is being researched.

CONCLUSIONS:

This work brings new insights on the Cognac ellagitannins content and how these molecules are influenced by aging and barrel toasting. Tastings will be performed to understand the organoleptic impact of these compounds.

DOI:

Publication date: September 15, 2021

Issue: Macrowine 2021

Type: Article

Authors

Mathilde Gadrat, Joel Lavergne, Catherine Emo, Pierre-Louis Teissedre, Kléopatra Chira,

1. Unité de recherche Œnologie, EA 4577, USC 1366 INRAE, ISVV, Univ. Bordeaux, Bordeaux INP, F33882 Villenave d’Ornon France 
2.   Courvoisier SAS, 2 places du château, 16200 Jarnac, France ,
Unité de recherche Œnologie, EA 4577, USC 1366 INRAE, ISVV, Univ. Bordeaux, Bordeaux INP, F33882 Villenave d’Ornon France 

Contact the author

Keywords

cognac, ellagitannins, mass spectrometry, toasting

Citation

Related articles…

Enological characters of thirty vines in four different zones of Tuscany

In the last few years the development of HPLC techniques together with multivariate statistical methods allowed to set methodics of large discriminant and classing efficacy in the study of wine-grapes.

Health benefits of wine industry by-products

The total global production of wine in 2021 was estimated at around 250 million hectoliters. The 30% of the total quantity of vinified grapes corresponds to wine by-products that represent nearly 20 million tons, of which 50% corresponds to the European Union. Wine by-products have been used for different purposes, in agriculture, cosmetics, pharmacy, biorefinery, feed, and the food

is the overall ecological awarness among Spanish winemakers related to their attitudes towards natural wines?

The Agenda 2030 of the EU sets out the main guidelines for transitioning towards a resilient, green and safe economy. To this regard, the wine sector is experiencing an ecological transition in different ways such as increasing the production of ecological crops, or promoting the production of wines under more environmental-friendly and healthier (i.e., lower levels of SO2) products. These alternatives to conventional production are a smaller proportion of wines, in constant growth and demand, and follow alternative and minority practices, which range from sustainable to deeply philosophical thoughts. Among these methods there are organic, biodynamic and, more recently, natural wines.

Assessing bunch architecture for grapevine yield forecasting by image analysis

It is fundamental for wineries to know the potential yield of their vineyards as soon as possible for future planning of winery logistics. As such, non-invasive image-based methods are being investigated for early yield prediction. Many of these techniques have limitations that make it difficult to implement for practical use commercially. The aim of this study was to assess whether yield can be estimated using images taken in-field with a smartphone at different phenological stages. The accuracy of the method for predicting bunch weight at different phenological stages was assessed for seven different varieties.

Drought effect on aromatic and phenolic potential of seven recovered grapevine varieties in Castilla-La Mancha region (Spain)

The effects of climate change are seriously affecting the quality of wine grapes. High temperatures and drought cause imbalances in the chemical composition of grapes. The result is overripe grapes with low acidity and high sugar content, which produce wines with excessive alcohol content, lacking in freshness and not very aromatic. As a consequence, the search of varieties with capacity of produce quality grapes in adverse climate conditions is a good alternative to preserve the sustainability of vineyards. In this work, quality parameters of seven Vitis vinifera L. cultivars (five whites and two reds) recently recovered from extinction and grown under two different hydric regimes (rainfed and irrigated) were analyzed during the 2020 vintage. At harvest time, weight of 100 berries, must physicochemical parameters (brix degree, total acidity, malic acid, pH), and carbon and oxygen isotope ratios (δ13C, δ18O) were determined. Subsequently, varietal aroma potential index (IPAv) and total polyphenol index (TPI) were analyzed. Quality parameters, IPAv and TPI, showed significant differences between varieties and water regimes. Both red varieties, Moribel and Tinto Fragoso, stood out for their high aromatic and phenolic potential, which was higher under rainfed regime. Regarding to white varieties, Montonera del Casar and Jarrosuelto stood out in terms of varietal aroma potential. Montonera del Casar high acidity in its musts and Jarrosuelto showed the highest berry weights.