Effect of Extraction Regimes on Antioxidant Potential of Rice (Oryza sativa) Bran Extracts

摘要

This work was carried out to assess the effect of different extraction methods on antioxidant potential of rice (Oryza sativa) bran. The bran samples after stabilization were extracted using soaking, stirring and shaking methods with 80% methanol (methanol:water; 80:20 v/v) and methanol. The amounts of total phenolics (TP) and total flavonoid (TF), % inhibition of peroxidation in linoleic acid system and DPPH radical scavenging activity of different rice bran extracts varied significantly (P < 0.05) with respect to extraction methods and solvents. TP, TF, % inhibition of peroxidation in linoleic acid system and DPPH radical scavenging activity of different rice bran extracts were found in range of 2.01- 3.47 mg/g of GAE, 1.34-2.06 mg/g of CE, 84.1-91.6 % and IC50 70.7-76.1 μg/mL, respectively. It was observed that 80% methanol exhibited better extraction yield and antioxidant activity. Among the three extraction procedures, stirring showed the superior efficiency in terms of yield of extracts, antioxidant potential than shaking and soaking. On the basis of present investigation, 80% methanol is most efficient solvent for the extraction of natural antioxidant compounds from rice bran extracts which is a potential source of natural antioxidants due to their marked antioxidant activity.