title: Low-interferences Determination of the Antioxidant Capacity in Fruits Juices Based on Xanthine Oxidase and Mediated Amperometric Measurements in the Reduction Mode.
abstract: A low-interferences enzymatic sensor for evaluating the antioxidant capacity was developed. Xanthine oxidase was used to produce superoxide radicals that spontaneously dismutate to hydrogen peroxide. Low xanthine concentrations were used to minimize the rapid dismutation of the superoxide radical before its fast reaction with antioxidants. The sensor operates in the reduction mode, and evaluations with low interferences of the antioxidant capacity are based on the detection of remaining hydrogen peroxide using Prussian blue electrodes at low potentials. The linear calibration graph is between 2 - 10 μM ascorbic acid. No interferences were observed from easily oxidisable substances including uric acid, which is produced in the enzymatic reaction or other substances usually found in foods. The method was used to evaluate the antioxidant capacity in different real juice samples.
authors: Centre of Bioanalysis, National Institute of Research and Development for Biological Sciences.
authors: Madalina-Petruta
authors: MP
authors: Bucur
authors: Maria-Cristina
authors: MC
authors: Radulescu
authors: Bogdan
authors: B
authors: Bucur
authors: Gabriel Lucian
authors: GL
authors: Radu
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry; D001205:Ascorbic Acid / Q000737:chemistry; D002138:Calibration; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D005295:Ferrocyanides / Q000737:chemistry; D005504:Food Analysis / Q000379:methods*; D005609:Free Radicals / Q000737:chemistry; D000067030:Fruit and Vegetable Juices / Q000032:analysis*; D006861:Hydrogen Peroxide / Q000737:chemistry; D016014:Linear Models; D010084:Oxidation-Reduction; D013481:Superoxides / Q000737:chemistry; D014969:Xanthine Oxidase / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D005295:Ferrocyanides; D005609:Free Radicals; D013481:Superoxides; D006861:Hydrogen Peroxide; D014969:Xanthine Oxidase; D001205:Ascorbic Acid; C000170:ferric ferrocyanide