Wheat bran extracts: a potent source of natural antioxidants for the stabilization of canola oil

Abstract

In the present work, the antioxidant activity of different solvent extracts of wheat (var. Inqalab 91) bran was evaluated following different antioxidant assays using canola oil as the oxidation substrate. The bran samples were extracted with 80% and 100% methanol and acetone. A preliminary assessment of the antioxidant activity of the 80 and 100% acetone and methanolic extracts of wheat bran was done by the measurement of % inhibition of peroxidation in a linoleic acid system, total phenolic contents (TPC) and bleachability of β-carotene in the linoleic acid system. Additionally, the canola oil samples were stabilized with crude concentrated extracts and subjected to ambient aging (6 months). The extent of oxidative deterioration was followed by the measurement of peroxide-, p-anisidine-, conjugated dienes-, and trienes- values. The results of ambient stored samples revealed a significant improvement in these oxidation parameters. The overall order of antioxidant activity of the extracts as determined by various antioxidant assays was determined to be; 80% methanolic extract > 100% methanolic extract > 80% acetone extracts . 100% acetone extract. The results of the present comprehensive analysis demonstrate that extracts of the wheat bran indigenous to Pakistan are a viable source of natural antioxidants and might be exploited for commercial and neutraceutical applications.

Keywords

• ambient storage
• β-carotene
• natural antioxidant
• percent inhibition
• tpc
• wheat bran