Study of wine tannins' interactions with polysaccharides from fungal source

CELL 24

Aurélie Bornet, Aureliebornet@aol.com1, Damien Guillaume2, Cédric Saucier2, and Pierre-Louis Teissedre, p.teissedre@u-bordeaux2.fr3. (1) Faculté de Pharmacie - UMR 1083 - Centre d'Oenologie -, University Montpellier 1, 15 Avenue Charles Flahault - BP14491, 34093 MONTPELLIER cedex 5, France, (2) Faculté d’Oenologie - UMR 1219 - Laboratoire de Chimie Appliquée, Université Bordeaux 2, 351, cours de la Libération, 33405 TALENCE cedex, France, (3) Faculté d’Oenologie - UMR 1219 - Laboratoire de Chimie Appliquée, Université Victor Segalen Bordeaux 2, 351, cours de la Libération, 33405 TALENCE cedex, France
Chitosan and chitin are polysaccharide polymers containing more than 5 000 glucosamine and acetylglucosamine units, respectively, and their molecular weights are over one million Daltons. chitin, chitosan and derivatives from fungal source could interact with tannins extracted from skins or seeds. A study of chitin, chitosan and derivatives on tanins was realized in model wines, and for different types of wines ( red, white, sweet). Tannins levels were followed for global level by bate-smith reaction, or by HPLC- DAD-UV for individuals compounds (monomers , dimers, gallotanins) after addition of chitin, chitosan and derivatives. We observed a reduction in tannins levels until 39% in model solutions. Catechin, epicatechin, dimers B1, B2, B3, B4 levels from skins or seed extracts can be significantly reduced in hydroalcoholic matrices. Apparent affinity constants obtained for the different polysaccharides (chitosane, chitosane glucan and chitin glucan) were as follows: seeds tannins >> skin tannins >> galloylated tanins. These polysaccharides should be favorable for the modulation of tannins perception in wine.
 

Poster Session
4:00 PM-6:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster

Division of Cellulose & Renewable Materials

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006