RT Journal Article SR Electronic T1 Structure and Properties of Wine Pigments and Tannins JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP 298 OP 305 DO 10.5344/ajev.2006.57.3.298 VO 57 IS 3 A1 Cheynier, Véronique A1 Dueñas-Paton, Montserrat A1 Salas, Erika A1 Maury, Chantal A1 Souquet, Jean-Marc A1 Sarni-Manchado, Pascale A1 Fulcrand, Hélène YR 2006 UL http://www.ajevonline.org/content/57/3/298.abstract AB Grape phenolics are structurally diverse, from simple molecules to oligomers and polymers that are usually designated “tannins,” referring to their ability to interact with proteins. Anthocyanin pigments and tannins are particularly important for red wine quality. Their extraction depends on their location in the berry and their solubility. All phenolic compounds are unstable and undergo numerous enzymatic and chemical reactions. Color and taste changes during red wine aging have been ascribed to anthocyanin-tannin reactions. The structures and properties of tannins and pigmented tannins from these reactions are often misunderstood. Current research on wine phenolic composition is reviewed, with emphasis on the following issues: (1) reactions of tannins yield both larger polymers and smaller species; (2) anthocyanin reactions can generate colorless species as well as polymeric and small various pigments; (3) some polymeric pigments undergo sulfite bleaching while some low molecular weight pigments do not; (4) polymers are both soluble and astringent, so the astringency loss during aging may involve cleavage rather than polymerization; and (5) sensory properties of anthocyanins and tannins are modulated by interactions with other wine components.