title: Application of a microplate-based ORAC-pyrogallol red assay for the estimation ofantioxidant capacity: First Action 2012.03.
abstract: A method was developed for microplate-based oxygen radicals absorbance capacity (ORAC) using pyrogallol red (PGR) as probe (ORAC-PGR). The method was evaluated for linearity, precision, and accuracy. In addition, the antioxidant capacity of commercial beverages, such as wines, fruit juices, and iced teas, was measured. Linearity of the area under the curve (AUC) versus Trolox concentration plots was [AUC = (845 +/- 110) + (23 +/- 2) [Trolox, microM]; R = 0.9961, n = 19]. Analyses showed better precision and accuracy at the highest Trolox concentration (40 microM) with RSD and recovery (REC) values of 1.7 and 101.0%, respectively. The method also showed good linearity for red wine [AUC = (787 +/- 77) + (690 +/- 60) [red wine, microL/mL]; R = 0.9926, n = 17], precision and accuracy with RSD values from 1.4 to 8.3%, and REC values that ranged from 89.7 to 103.8%. Red wines showed higher ORAC-PGR values than white wines, while the ORAC-PGR index of fruit juices and iced teas presented a wide range of results, from 0.6 to 21.6 mM of Trolox equivalents. Product-to-product variability was also observed for juices of the same fruit, showing the differences between brands on the ORAC-PGR index.
authors: Pontificia Universidad Católica de Chile, Facultad de Química, Departamento de Farmacia, C.P. 782 0436, Santiago, Chile.
authors: Rocío
authors: R
authors: Ortiz
authors: Mónica
authors: M
authors: Antilén
authors: Hernán
authors: H
authors: Speisky
authors: Margarita E
authors: ME
authors: Aliaga
authors: Camilo
authors: C
authors: López-Alarcón
authors: Steve
authors: S
authors: Baugh
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry*; D019540:Area Under Curve; D001628:Beverages / Q000032:analysis; D002839:Chromans / Q000737:chemistry; D019793:Fluorescein; D005504:Food Analysis; D005609:Free Radicals / Q000032:analysis; D005638:Fruit / Q000737:chemistry; D006801:Humans; D007202:Indicators and Reagents; D010944:Plants / Q000737:chemistry; D011748:Pyrogallol / Q000031:analogs & derivatives* / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000032:analysis; D012015:Reference Standards; D015203:Reproducibility of Results; D012996:Solutions; D013662:Tea / Q000737:chemistry; D014920:Wine / Q000032:analysis
chemical_list: D000975:Antioxidants; D002839:Chromans; D005609:Free Radicals; D007202:Indicators and Reagents; D017382:Reactive Oxygen Species; D012996:Solutions; D013662:Tea; D011748:Pyrogallol; C058731:pyrogallol sulfonphthalein; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid; D019793:Fluorescein