Oak wood ellagitannins influence on the organoleptic perception of red wine
Some wood substances such as ellagitannins can be extracted during wine ageing in oak barrels. Recently, there has been an increasing interest in ellagitannins because they have been implicated in numerous biological properties, including antioxidant, anticancer, anti-inflammatory, antibacterial, and anti-HIV replication activities. [1,2,3] The impact of ellagitannins concentration on the organoleptic perception of red wine is still be under investigation.  In our research, we classified staves according to their ellagitannins level using a NIRS online procedure (Oakscan®)  and were able to correlate the NIRS classification with the level of ellagitannins estimated by HPLC-UV. The different types of staves were added to red wine during its ageing and the extraction and evolution of the main ellagitannins was monitored by HPLC-UV. The influence of ellagitannins levels on wine perception was estimated by a trained judge's panel. It appears that the staves classification estimated by NIRS procedure on wood was in good agreement with the total level ellagitannins extracted by organic solvents as well as the level of ellagitannins quantified in red wines aged during 4 months with the classified staves. The level of ellagitannins was estimated by quantification of ellagic acid released during hydrolysis as well as by quantification of each specific ellagitannins: vescalagin, castalagin, grandinin, roburins (A, B, C, D, E) by HPLC-UV-MS. The level of ellagitannins in red wine seems to have an impact on the roundness of the wines. Moreover, it appears that astringency and bitterness were not negatively impacted by the level of ellagitannins in wine.
References: 1. Quideau, S., (2009), Chemistry and biology of ellagitannins: An underestimated class of bioactive, World Scientific: Singapore.
2. Fernandes, A., Fernandes, I., Cruz, C,. Mateus, N., Cabral, M., and De Freitas, V., (2009), Antioxidant and Biological Properties of Bioactive Phenolic Compounds from Quercus suber, J. Agric. Food Chem., 57, 11154–11160.
3. L.M. Bedoya, L.M., M.J. Abad, M.J., Sanchez-Palomino. S., Alcami. J., Bermejo. P., (2010), Ellagitannins from Tuberaria lignosa as entry inhibitors of HIV, Phytomedicine 17, 69–74.
4. Quinn M.K. and Singleton V.L.; Isolation and identification of ellagitanins from white oak wood and an estimation of their role in wine; 1985, Am. J. Enol. Vitic, 36, 148–155.
5. Giordanengo, T., Charpentier, J.P., Boizot, N., Roussel, S., Roger, J.M., Chaix, G., Robin, C. and Mourey, N., (2009), OAKSCAN™: Procédé de mesure rapide et non destructif des polyphénols du bois de chêne de tonnellerie; Revue française d'œnologie, 234, 10–15.