title: Anthocyanins influence tannin-cell wall interactions.
abstract: The rate of tannin extraction was studied in a vinification of red grapes and the results compared with another vinification made with white grapes fermented as for typical red wine, in the presence of skins and seeds. Even though the grapes presented a quite similar skin and seed tannin content, the differences in tannin concentration between both vinifications was very large, despite the fact that the only apparent difference between the phenolic composition of both wines was the anthocyanin content. This suggests that anthocyanins play an important role in tannin extractability, perhaps because they affect the extent of the tannin-cell wall interaction, a factor that largely controls the resulting quantity of tannins in wines. To confirm this observation, the effect of anthocyanins on the tannin extractability from grape seeds and skin and on the interaction between tannins and grape cell walls suspended in model solutions were studied. The results indicated that anthocyanins favored skin and seed tannin extraction and that there is a competition for the adsorption sites between anthocyanins and tannins that increases the tannin content when anthocyanins are present.
authors.affiliation: Department of Food Science and Technology, Faculty of Veterinary, University of Murcia, Campus de Espinardo, 30071 Murcia, Spain.
authors.forename: Ana Belén
authors.initials: AB
authors.lastname: Bautista-Ortín
authors.affiliation: Department of Food Science and Technology, Faculty of Veterinary, University of Murcia, Campus de Espinardo, 30071 Murcia, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Martínez-Hernández
authors.affiliation: Department of Food Science and Technology, Faculty of Veterinary, University of Murcia, Campus de Espinardo, 30071 Murcia, Spain.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Ruiz-García
authors.affiliation: Instituto Murciano de Investigación y Desarrollo Agroalimentario, Ctra. La Alberca, s/n, 30150 Murcia, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Gil-Muñoz
authors.affiliation: Department of Food Science and Technology, Faculty of Veterinary, University of Murcia, Campus de Espinardo, 30071 Murcia, Spain. Electronic address: encarnag@um.es.
authors.forename: Encarna
authors.initials: E
authors.lastname: Gómez-Plaza
mesh_terms: D000872:Anthocyanins / Q000737:chemistry*; D002473:Cell Wall / Q000737:chemistry; D005285:Fermentation; D013634:Tannins / Q000737:chemistry*; D027843:Vitis / Q000737:chemistry*; D014920:Wine / Q000032:analysis
chemical_list: D000872:Anthocyanins; D013634:Tannins
keywords: Adsorption; Anthocyanins; Extractability; Phloroglucinolysis; Polysaccharides; Proanthocyanidins; Size exclusion chromatography