Antioxidant capacity of phenolic compounds in acidic medium: A pyrogallol red-based ORAC (oxygen radical absorbance capacity) assay
Author
dc.contributor.author
Atala, E.
Author
dc.contributor.author
Aspée, Alexis
Author
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Speisky Cosoy, Hernán
Author
dc.contributor.author
Lissi Gervaso, Eduardo A.
Author
dc.contributor.author
López Alarcón, Camilo
Admission date
dc.date.accessioned
2018-12-20T15:10:54Z
Available date
dc.date.available
2018-12-20T15:10:54Z
Publication date
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2013
Cita de ítem
dc.identifier.citation
Journal of Food Composition and Analysis, Volumen 32, Issue 2, 2018, Pages 116-125
Identifier
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08891575
Identifier
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10.1016/j.jfca.2013.09.007
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/158302
Abstract
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A novel ORAC (oxygen radical absorbance capacity) assay to assess antioxidant capacity of phenolic compounds in near-gastric conditions (pH 2.0) is presented. AAPH (2,2'-azo-bis(2-amidinopropane)dihydrochloride) was used as peroxyl radicals source, and fluorescein, pyranine and pyrogallol red were employed as target molecules. Only pyrogallol red (PGR) showed a behavior compatible with an ORAC assay under acidic conditions (ORAC-PGRa). Excepting Trolox and ascorbic acid, phenolic compounds protected PGR, giving kinetic profiles without the presence of an induction time. ORAC-PGRa values, which reflect the reactivity of the antioxidants toward peroxyl radicals, ranged from 0.2 (caffeic acid) to 29.1 (myricetin) gallic acid equivalents. The ORAC-PGRa method showed analytical parameters in agreement with other ORAC-like assays and was applied to wines, teas, commercial juices and herb infusions, peach juice being the sample with the highest ORAC-PGRa value (7.1mM gallic acid equivalents).