ANTIOXIDANT CAPACITY OF THE GREEN LEAFY VEGETABLES USING OXYGEN RADICAL ANTIOXIDANT CAPACITY (ORAC), 2,2′-AZINO-BIS (3-ETHYLBENZOTHIAZOLINE-6-SULPHONIC ACID(ABTS) AND 2,2-DIPHENYL-1-PICRYLHYDRAZYL (DPPH) ASSAYS

Abstract

Antioxidants are believed to play a very important role in the body defence system against reactive oxygen species (ROS), the harmful by-products that are generated during normal aerobic cell respiration. The objective of this study was to determine the antioxidant capacity in green leafy vegetables using ORAC, ABTS, and DPPH assays of different polyphenol fractions (free phenolic, alkaline hydrolysate, acidic hydrolysate). The antioxidant capacity of the identified free and bound phenolic acid content was measured using different assays including ORAC, ABTS, and DPPH assay (end-point assay and kinetic assay). Only hydrophilic antioxidant activities of all selected samples were examined using ORAC assay. Strong correlations were observed in acidic and alkaline hydrolysate fractions (p