Unravelling the total antioxidant capacity of pinotage wines: Contribution of phenolic compounds

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dc.contributor.authorDe Beer D.
dc.contributor.authorJoubert E.
dc.contributor.authorMarais J.
dc.contributor.authorManley M.
dc.date.accessioned2011-05-15T15:56:52Z
dc.date.available2011-05-15T15:56:52Z
dc.date.issued2006
dc.description.abstractThe total antioxidant capacity (TAC) and phenolic composition of 139 Pinotage wines (2002 and 2003 vintages) were determined using the 2,2′-azino-di(3-ethylbenzo-thialozine-sulfonic acid) scavenging assay and high-performance liquid chromatography, respectively. The contribution of individually quantified phenolic compounds to the wine TAC was calculated using their concentrations and Trolox equivalent antioxidant capacity (TEAC) values. The TEAC values of quercetin-3-galactoside, isorhamnetin, and peonidin-3-glucoside are reported for the first time. Between 11 and 24% of the measured TAC of Pinotage wines was explained by the sum of the calculated contributions of their quantified phenolic compounds comprising monomeric phenolic compounds and procyanidin B1. Ultrafiltration was carried out to attempt separation of monomeric and polymeric phenolic compounds. Analysis of ultrafiltration permeates and retentates enabled estimation of the TAC contribution of large molecular weight (MW) unknown compounds (46%) (>50 kDa), including oligomeric and polymeric phenolic compounds and small MW unknown compounds (34%) (<50 kDa). Three mixtures, containing 12 phenolic compounds in typical concentrations expected in Pinotage wines, exhibited 16-23% synergistic antioxidant activity. This suggests that synergy between phenolic compounds does play a role in the wine TAC but that it does not explain the large discrepancy between measured and calculated TAC values. © 2006 American Chemical Society.
dc.description.versionArticle
dc.identifier.citationJournal of Agricultural and Food Chemistry
dc.identifier.citation54
dc.identifier.citation8
dc.identifier.issn218561
dc.identifier.other10.1021/jf052766u
dc.identifier.urihttp://hdl.handle.net/10019.1/10081
dc.subject2,2' azino di (3 ethylbenzothiazoline) 6 sulfonic acid
dc.subject2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid
dc.subject6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid
dc.subjectantioxidant
dc.subjectbenzothiazole derivative
dc.subjectchroman derivative
dc.subjectphenol derivative
dc.subjectscavenger
dc.subjectsulfonic acid derivative
dc.subjecttrolox C
dc.subjectarticle
dc.subjectultrafiltration
dc.subjectwine
dc.subjectAntioxidants
dc.subjectBenzothiazoles
dc.subjectChromans
dc.subjectFree Radical Scavengers
dc.subjectPhenols
dc.subjectSulfonic Acids
dc.subjectUltrafiltration
dc.subjectWine
dc.titleUnravelling the total antioxidant capacity of pinotage wines: Contribution of phenolic compounds
dc.typeArticle
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