Antioxidant capacity of phytic acid purified from rice bran

Abstract

Rice bran is a by-product of rice processing industry, with high levels of phytic acid or phytate. Considering phytic acid antioxidant activity, its various applications and its high concentration in rice bran, this study had the objective of evaluating the antioxidant capacity of purified phytic acid from rice bran using three different methods. Using of 2,4,6-tripyridil-s-triazine or method of FRAP (Ferric Reducing Antioxidant Power), reducing Fe 2+ activity was not detected for standard or purified phytic acid. With BPS (bathophenanthroline) method, the Fe 2+ chelator activity of standard phytic acid and rice bran phytic acid were dependent on the concentration and contact time and were observed IC 50 values of 4.39 mg mL -1 and IC 50 of 7.54 mg mL -1 , respectively. By the deoxyribose method, the standard phytic acid inhibited the hydroxyl radical with an IC 50 of 0.70 mg mL -1 while the rice bran phytic acid showed a maximum inhibitory activity of 40% associated to its chelating capacity and confirm this important antioxidant capacity.