title: New Electrochemical Evaluation of the Antioxidant Capacity of Beverages with Polyoxometalates as Redox Probes.
abstract: A new method was developed to evaluate antioxidant activity based on the redox properties of polyoxometalates, which are partially reduced by antioxidants to generate a limiting potential. The polyoxometalates [PMo12O40](3-), [PVW11O40](4-) and [SV2W10O40]4- formed in situ were used as electrochemical probes for the new evaluation method, and their formation conditions were optimized to evaluate the antioxidant activities of gallic acid, ellagic acid, catechin, quercetin, morin, trans-ferulic acid, sesamol, α-tocopherol, δ-tocopherol and L-ascorbic acid. The observed difference between initial potential and limiting potential (ΔE) were compared with spectrophotometrically evaluated antioxidant activities. In addition, the antioxidant capacities of five beverages (Japanese green tea, concentrated catechin-containing green tea, grapefruit juice, red wine and Japanese sake) were evaluated.
authors: Department of Applied Chemistry, Faculty of Science, Kochi University.
authors: Tadaharu
authors: T
authors: Ueda
authors: Takashi
authors: T
authors: Okumura
authors: Yukino
authors: Y
authors: Tanaka
authors: Saki
authors: S
authors: Akase
authors: Tomoko
authors: T
authors: Shimamura
authors: Hiroyuki
authors: H
authors: Ukeda
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001628:Beverages / Q000032:analysis*; D055664:Electrochemical Techniques / Q000379:methods*; D015335:Molecular Probes; D010084:Oxidation-Reduction; D017973:Tungsten Compounds / Q000737:chemistry*; D000099294:Polyoxometalates
chemical_list: D000975:Antioxidants; D015335:Molecular Probes; D017973:Tungsten Compounds; C102296:polyoxometalate I; D000099294:Polyoxometalates