Assessment of Antioxidant Potential of Dietary Components

Abstract

Antioxidants neutralize or mitigate the harmful effects of free radicals. Such antioxidants may be classed as either enzymatic or nonenzymatic. Some components in the diet act as important antioxidants as they may have direct antioxidant activity or are a component of antioxidant systems. Free radical-mediated stress arises when body fails to ameliorate the excess generation of free radicals. In such circumstances the need for supplementary or other dietary antioxidants arises. As a consequence, it is necessary to assay antioxidants status in subjects or antioxidant potential of novel dietary components. Several techniques have been developed to measure the antioxidant potential of dietary components. We describe antioxidants in general, then various platforms using spectroscopic, chromatographic, electrochemical, and photochemical methods. The following in assays and protocols are reviewed: hydrogen atom transfer, oxygen radical absorbance capacity, diphenyl-1-picrylhydrazyl radical scavenging, trolox equivalent antioxidant capacity, ferric-reducing antioxidant power, total radical-trapping antioxidant parameter, metal-chelating capacity, hydroxyl radical antioxidant capacity, diene conjugates, thiobarbituric acid reactive substances, hexanal, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid, phycoerythrin, bleomycin-iron, copper-1,10-phenanthroline complex, peroxynitrite, lipid-soluble antioxidants, beta-carotene bleaching, hydroxyl radical scavenging, superoxide anion radical scavenging capacity, ferrous oxidation-xylenol orange, ferric thiocyanate, nonenzymatic in vivo and enzymatic in vivo assays. ? 2018 Elsevier Inc. All rights reserved.