title: Effect of the solvatation shell exchange on the formation of malvidin-3-O-glucoside-ellagic acid complexes.
abstract: The interaction of malvidin-3-O-glucoside with ellagic acid was studied in aqueous solutions in dependence of the ethanol content of the samples. The results show significant changes of the thermodynamic parameters when the ethanol content exceeds 8%vol. The quantum chemical calculations and the solvent relaxation measurements validate that the solvatation shell of the malvidin-ellagic acid complexes changes from water to ethanol around this critical alcoholic concentration. The change of the solvate shell is accompanied by increasing copigmentation; i.e., higher "multi-sandwich" complexes are formed. According to the considerable role of this interaction (namely copigmentation) in the formation of color in red wines, our results have several consequences for the winemaking process with regard to the stabilization of wine color.
authors.affiliation: University of Pécs, Department of General and Physical Chemistry, IfjúsAg u 6, 7624, Pécs, Hungary. kunsagi@gamma.ttk.pte.hu
authors.forename: Sandor
authors.initials: S
authors.lastname: Kunsagi-Maté
authors.forename: Erika
authors.initials: E
authors.lastname: Ortmann
authors.forename: Laszló
authors.initials: L
authors.lastname: Kollar
authors.forename: Martin Pour
authors.initials: MP
authors.lastname: Nikfardjam
mesh_terms: D000872:Anthocyanins / Q000737:chemistry*; D004610:Ellagic Acid / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D005960:Glucosides; D012995:Solubility; D012996:Solutions; D013816:Thermodynamics; D014920:Wine
chemical_list: D000872:Anthocyanins; D005960:Glucosides; D012996:Solutions; D004610:Ellagic Acid; D000431:Ethanol; C458419:malvidin-3-glucoside