title: PVPP-polyphenol complexes: a molecular approach.
abstract: In dry white wines, two different forms of instability occur: (i) substantial yellow or yellow-green deposits are observed principally due to flavonol quercetin; and (ii) protein instability leads to protein casse. Polyvinyl polypyrrolidone (PVPP) is used to adsorb phenols from beverages, and bentonite is used to eliminate heat instable protein. However, in both cases, their effects are still largely unknown. This study uses a multitechnique approach to gain a better molecular understanding of the association of polyphenol aglycones with PVPP compared to that of glucosides with PVPP. The work demonstrates, that with aglycones, three forces drive complex formation: hydrophobic interaction, H bonds, and van der Waals bonds. With glucosides, the sugar moiety removes or reduces these driving forces. Thus, if the interaction between proteins and polyphenols is responsible for haze and precipitates, as is classically assumed, PVPP could prevent quercetin sedimentation.
authors.affiliation: Laboratoire de Physique et Biophysique, GESVAB EA 3675, Université de Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Laborde
authors.forename: Virginie
authors.initials: V
authors.lastname: Moine-Ledoux
authors.forename: Tristan
authors.initials: T
authors.lastname: Richard
authors.forename: Cédric
authors.initials: C
authors.lastname: Saucier
authors.forename: Denis
authors.initials: D
authors.lastname: Dubourdieu
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Monti
mesh_terms: D055598:Chemical Phenomena; D011232:Chemical Precipitation; D002627:Chemistry, Physical; D005419:Flavonoids / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry*; D059808:Polyphenols; D011205:Povidone / Q000031:analogs & derivatives* / Q000737:chemistry; D011794:Quercetin / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D014920:Wine / Q000032:analysis
chemical_list: D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; C077842:polyvinylpolypyrrolidone; D011794:Quercetin; D011205:Povidone