title: Entropy-driven complex formation of malvidin-3-O-glucoside with common polyphenols in ethanol-water binary solutions.
abstract: The complex formation of malvidin-3-O-glucoside with several polyphenols, the so-called "copigmentation" phenomenon, was studied in aqueous solutions. To simulate the copigmentation process during fermentation, the stability of the formed complexes was examined in dependence of the ethanol content of the aqueous solution. Results indicate that stronger and larger complexes are formed, when the ethanol content exceeds a critical margin of 8vol.% However, the size of complexes of malvidin/procyanidin and malvidin/epicatechin is drastically reduced above this critical concentration. Fluorescence lifetime and solvent relaxation measurements give insight into the particular processes at molecular level and will help us comprehend the first important steps during winemaking in order to recommend an optimized winemaking technology to ensure extraordinary colour stability in red wines.
authors.affiliation: University of Pécs, Department of General and Physical Chemistry, Ifjúság u. 6, 7624 Pécs, Hungary. kunsagi@gamma.ttk.pte.hu
authors.forename: Sándor
authors.initials: S
authors.lastname: Kunsági-Máté
authors.forename: Erika
authors.initials: E
authors.lastname: Ortmann
authors.forename: László
authors.initials: L
authors.lastname: Kollár
authors.forename: Martin Pour
authors.initials: MP
authors.lastname: Nikfardjam
mesh_terms: D000872:Anthocyanins / Q000737:chemistry*; D019277:Entropy; D000431:Ethanol / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry*; D005960:Glucosides; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry*; D059808:Polyphenols; D012996:Solutions; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D000872:Anthocyanins; D005419:Flavonoids; D005960:Glucosides; D010636:Phenols; D059808:Polyphenols; D012996:Solutions; D012997:Solvents; D014867:Water; D000431:Ethanol; C458419:malvidin-3-glucoside