title: Analysis of polymeric phenolics in red wines using different techniques combined with gel permeation chromatography fractionation.
abstract: A multiple-step analytical method was developed to improve the analysis of polymeric phenolics in red wines. With a common initial step based on the fractionation of wine phenolics by gel permeation chromatography (GPC), different analytical techniques were used: high-performance liquid chromatography-diode array detection (HPLC-DAD), HPLC-mass spectrometry (MS), capillary zone electrophoresis (CZE) and spectrophotometry. This method proved to be valid for analyzing different families of phenolic compounds, such as monomeric phenolics and their derivatives, polymeric pigments and proanthocyanidins. The analytical characteristics of fractionation by GPC were studied and the method was fully validated, yielding satisfactory statistical results. GPC fractionation substantially improved the analysis of polymeric pigments by CZE, in terms of response, repeatability and reproducibility. It also represented an improvement in the traditional vanillin assay used for proanthocyanidin (PA) quantification. Astringent proanthocyanidins were also analyzed using a simple combined method that allowed these compounds, for which only general indexes were available, to be quantified.
authors.affiliation: Department of Agriculture and Food Science, University of La Rioja, C/Madre de Dios 51, 26006 Logroño, La Rioja, Spain. zenaida.guadalupe@daa.unirioja.es
authors.forename: Zenaida
authors.initials: Z
authors.lastname: Guadalupe
authors.forename: Alberto
authors.initials: A
authors.lastname: Soldevilla
authors.forename: María-Pilar
authors.initials: MP
authors.lastname: Sáenz-Navajas
authors.forename: Belén
authors.initials: B
authors.lastname: Ayestarán
mesh_terms: D005591:Chemical Fractionation / Q000379:methods; D002850:Chromatography, Gel / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis*; D013058:Mass Spectrometry; D010636:Phenols / Q000032:analysis*; D059808:Polyphenols; D044945:Proanthocyanidins / Q000032:analysis; D014920:Wine / Q000032:analysis*
chemical_list: D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D044945:Proanthocyanidins