Cited by 6,162Phytochemicals and Antioxidant ActivitiesFree Radicals and AntioxidantsAntioxidant Activity and Oxidative Stress

The Chemistry behind Antioxidant Capacity Assays

Huang, Dejian, Ou, Boxin, Prior, Ronald L.·2005·Journal of Agricultural and Food Chemistry

Abstract

This review summarizes the multifaceted aspects of antioxidants and the basic kinetic models of inhibited autoxidation and analyzes the chemical principles of antioxidant capacity assays. Depending upon the reactions involved, these assays can roughly be classified into two types: assays based on hydrogen atom transfer (HAT) reactions and assays based on electron transfer (ET). The majority of HAT-based assays apply a competitive reaction scheme, in which antioxidant and substrate compete for thermally generated peroxyl radicals through the decomposition of azo compounds. These assays include inhibition of induced low-density lipoprotein autoxidation, oxygen radical absorbance capacity (ORAC), total radical trapping antioxidant parameter (TRAP), and crocin bleaching assays. ET-based assays measure the capacity of an antioxidant in the reduction of an oxidant, which changes color when reduced. The degree of color change is correlated with the sample's antioxidant concentrations. ET-based assays include the total phenols assay by Folin-Ciocalteu reagent (FCR), Trolox equivalence antioxidant capacity (TEAC), ferric ion reducing antioxidant power (FRAP), "total antioxidant potential" assay using a Cu(II) complex as an oxidant, and DPPH. In addition, other assays intended to measure a sample's scavenging capacity of biologically relevant oxidants such as singlet oxygen, superoxide anion, peroxynitrite, and hydroxyl radical are also summarized. On the basis of this analysis, it is suggested that the total phenols assay by FCR be used to quantify an antioxidant's reducing capacity and the ORAC assay to quantify peroxyl radical scavenging capacity. To comprehensively study different aspects of antioxidants, validated and specific assays are needed in addition to these two commonly accepted assays.

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Crossref · 10.1021/jf030723c

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Authors
Huang, D., Ou, B., & Prior, R. L.
Affiliations
Agricultural Research Service (US)
Venue
Journal of Agricultural and Food Chemistry
Published
2005-02-25
Volume
53
Issue
6
Pages
1841-1856
ISSN
  • 0021-8561 (ISSN-L)
  • 1520-5118
OpenAlex
W1998936301
Cited by
6,162
References
87
Citations by year
2026: 231 · 2025: 238 · 2024: 283 · 2023: 305 · 2022: 384 · 2021: 383 · 2020: 353 · 2019: 329 · 2018: 332 · 2017: 346 · 2016: 350 · 2015: 427 · 2014: 394 · 2013: 398 · 2012: 360
FWCI
8.17
Type
journal article
Language
en
Open access
closed
Locations
  • Journal of Agricultural and Food Chemistry (publishedVersion)
  • PubMed (publishedVersion)
  • National University of Singapore (submittedVersion)
Topics
  • Health Sciences › Medicine › Biochemistry › Phytochemicals and Antioxidant Activities
  • Physical Sciences › Chemistry › Organic Chemistry › Free Radicals and Antioxidants
  • Health Sciences › Medicine › Biochemistry › Antioxidant Activity and Oxidative Stress
Keywords
antioxidants, autoxidation kinetics, hydrogen atom transfer, electron transfer, peroxyl radical scavenging, azo compounds, ORAC, total radical-trapping antioxidant parameter, Trolox equivalent antioxidant capacity, FRAP, DPPH, singlet oxygen, superoxide, peroxynitrite, hydroxyl radicals, reducing power
MeSH terms
Antioxidants, Chromans, Copper, Ferric Compounds, Free Radicals, Hydrogen Peroxide, Kinetics, Molybdenum, Oxidation-Reduction, Oxygen, Phenols, Lipid Peroxidation, Free Radical Scavengers, Reactive Oxygen Species, Hydroxyl Radical, Tungsten Compounds, Singlet Oxygen, Peroxynitrous Acid

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