Macrowine 2021
IVES 9 IVES Conference Series 9 Influence of toasting oak wood on ellagitannin structures

Influence of toasting oak wood on ellagitannin structures

Abstract

Ellagitannins (ETs) have been reported to be the main phenolic compounds found in oak wood. These compounds, belonging to the hydrolysable tannin class of polyphenols, are esters of hexahydroxydiphenic acid (HHDP) and a polyol, usually glucose or quinic acid. They own their name to their capacity to be hydrolysed and liberate ellagic acid and they have an impact on astringency and bitterness sensation, which is strongly dependant on their structure. The toasting phase is particularly crucial in barrels fabrication and influences wood composition. Burning the inner oak wood barrels surface with an open fire inducing severe changes in ellagitannins structures and compositions. Up to now thermal ellagitannin products or the reaction mechanisms underlying the ellagitannin degradation are not well searched, thus the goal of the present study is to research oak wood ellagitannin changes during toasting. For this purpose a purification protocol was established, 100 mg ellagitannins crude extract was fractionated on Toyopearl TSK HW-40 (F) gel from Tosoh Corp, ellagitannins were eluted in the acetone/water fraction. This fraction was fractionated for two times on a C-18 column. The final fraction containing only the eight principal ellagitannins was dry-heated in a lab oven for 60 min at 220 °C. After cooling, it was further fractionated on C-18 column and separated by means of preparative HPLC before being injected in UPLC/TOF-MS. Reduction process is occuring during toasting whereas oxydation can occur without heating; Thus vescalagin, is reduced into deoxyvescalagin whereas castalagin oxidation form is presented before and after toasting. Additionally to deoxyvescalagin, other ellagitannin derivatives which showed [M-H]-ion peak at m/z 1055.0631, 1041.0792, 1011.0756 and 971.0456 were produced by the toasting and identified for the first time. LC-MS/MS analyses gave strong evidence that decarboxylations as well as ellagic acid loss are the key steps in ellagitanin thermal degradation.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Kleopatra Chira*, Michael Jourdes, Pierre Louis Teissedre

*Institut des sciences de la vigne et du vin

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Influence of wood chips addition during alcoholic fermentation on wine phenolic composition

This study investigates the effect of wood chips addition during the alcoholic fermentation on the phenolic
composition of the produced wines. A series of wood chips, originating from American, French, Slavonia
oak and Acacia were added at the beginning of wine alcoholic fermentation. Besides, a mixture consisting
of 50% French and 50% Americal oak chips were added during the experimentation. The wine samples
were analyzed one month after the end of malolactic fermentation, examining various chemical
parameters such as total anthocyanins, total phenolic content, tannins combined with protein (BSA) and
ellagitannin content.

Read More

On the losses of dissolved CO2 from laser-etched champagne glasses under standard tasting conditions

Under standard champagne tasting conditions, the complex interplay between the level of dissolved CO2 found in champagne, its temperature, the glass shape, and the bubbling rate, definitely impacts champagne tasting by modifying the neuro-physico-chemical mechanisms responsible for aroma release and flavor perception. Based on theoretical principles combining heterogeneous bubble nucleation, ascending bubble dynamics and mass transfer equations, a global model is proposed (depending on various parameters of both the wine and the glass itself), which quantitatively provides the progressive losses of dissolved CO2 from laser-etched champagne glasses.

Read More

Determination of metallic elements in Chilean wines by atomic absorption spectroscopy and inductively coupled plasma–mass spectrometry

The chemical composition of wines depends on series of variables such as the type of grape, edaphoclimatic conditions, and viticulture and winemaking practices employed during production. Metallic elements play a significant role during winemaking (e.g. as catalysts of oxidation reactions) and have been previously employed for the classification of wines according to provenance. In this work, we focused on the analysis of metallic elements (K, Na, Ca, Zn, Cu, Fe, Mg, Mn, Ni, Cr, Al, Pb, Cd, Hg, Se, Co, Sn and As) in 145 Chilean wine samples (102 reds and 43 white wines), of seven grape varieties, and five of the major wine producing regions in Chile.

Read More

Characterization of non-Saccharomyces yeast and its interaction with Saccharomyces cerevisiae with investigation of fermentation kinetics and aromatic composition

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.20.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...
Read More

Anthropogenic factors in modulations of fungal populations from grapes to wines and their repercussions on wine characteristics

The effects of anthropogenic activities on vineyard (different plant protections) and in winery
(pressing/clarification step, addition of sulfur dioxide) on fungal populations from grape to wine were studied. The studied anthropogenic activities modify the fungal diversity. Thus, lower biodiversity of grapes from organic modality was measured for the three vintages considered compared to biodiversity from ecophyto modality and conventional modality. The pressing / clarification steps strongly modify fungal populations and the influence of the winery flora is highlighted.

Read More