title: Vitamin C equivalent antioxidant capacity (VCEAC) of phenolic phytochemicals.
abstract: To express the antioxidant capacity of plant foods in a more familiar and easily understood manner (equivalent to vitamin C mg/100 g), two stable radical species, ABTS(*)(-) and DPPH(*), commonly used for antioxidant activity measurements, were employed independently to evaluate their efficacies using apple polyphenolic extracts and seven polyphenolic standards including synthetic Trolox. Their antioxidant activities were expressed as vitamin C equivalent antioxidant capacity (VCEAC) in mg/100 g apple or mg/100 mL of the reference chemical compounds in 10 and 30 min using the ABTS(*)(-) and DPPH(*) scavenging assays, respectively. The antioxidant capacity of Gala apples and seven phenolic standards, determined by both ABTS(*)(-) and DPPH(*) scavenging assays, showed a dose-response of the first-order. Fresh Gala apples had a VCEAC of 205.4 +/- 5.6 mg/100 g using the ABTS assay, and the relative VCEACs of phenolic standards were as follows: gallic acid > quercetin > epicatechin > catechin > vitamin C > rutin > chlorogenic acid > Trolox. With the DPPH radical assay, the VCEAC of fresh Gala apples was 136.0 +/- 6.6 mg/100 g, and the relative VCEACs of seven phenolic standards were, in decreasing order, as follows: gallic acid > quercetin > epicatechin > catechin > or = vitamin C > Trolox > rutin > chlorogenic acid. Because the ABTS assay can be used in both organic and aqueous solvent systems, employs a specific absorbance at a wavelength remote from the visible region, and requires a short reaction time, it is a more desirable method than the DPPH assay. Therefore, it is recommended that antioxidant capacity be expressed as vitamin C mg/100 g equivalent (VCEAC) using the ABTS assay.
authors.affiliation: Department of Food Science and Technology, Cornell University, Geneva, New York 14456, USA.
authors.forename: Dae-Ok
authors.initials: DO
authors.lastname: Kim
authors.forename: Ki Won
authors.initials: KW
authors.lastname: Lee
authors.forename: Hyong Joo
authors.initials: HJ
authors.lastname: Lee
authors.forename: Chang Yong
authors.initials: CY
authors.lastname: Lee
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D002392:Catechin / Q000494:pharmacology; D002726:Chlorogenic Acid / Q000494:pharmacology; D002839:Chromans / Q000494:pharmacology; D016166:Free Radical Scavengers; D005609:Free Radicals; D005707:Gallic Acid / Q000494:pharmacology; D007700:Kinetics; D027845:Malus / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000494:pharmacology*; D010851:Picrates; D010936:Plant Extracts / Q000737:chemistry*; D010945:Plants, Edible / Q000737:chemistry*; D011794:Quercetin / Q000494:pharmacology; D012431:Rutin / Q000494:pharmacology; D013451:Sulfonic Acids
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D002839:Chromans; D016166:Free Radical Scavengers; D005609:Free Radicals; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D002726:Chlorogenic Acid; D012431:Rutin; D005707:Gallic Acid; D002392:Catechin; D011794:Quercetin; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid