Chemical analysis and antioxidant properties of foxtail millet bran extracts

Abstract

The aim of this research was to extract phenolic compounds and assess the antioxidant potential of defatted foxtailmillet bran (DFMB) extracts. Distilled water, 30%, 50%, and 70% ethanol were used as solvent for extraction. The proximatecomposition, fatty acid analysis, total phenolic content and extraction yield were carried out. The antioxidant efficacies ofDFMB extract were tested using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid(ABTS), superoxide radical and reducing power. The highest inhibitory concentration (IC50) values scavenging on DPPH,ABTS and superoxide radicals were in the range of 0.131±0.002, 0.795±0.003, and 0.158±0.009 mg/ml, for distilled water, and 30and 50% ethanol extracts respectively. The reducing power increased with increase of sample concentration. Total phenoliccontent ranged from 21.49±3.26 to 29.39±1.36 gallic acid equivalent (GAE)/100 g extract. The phenolic content and antioxidantactivity in DFMB extracts were significantly correlated (p<0.05). These results indicated that 50% ethanol extract fromDFMB appeared to be the most promoting phenolic compound with substantial antioxidant activity.

Keywords

• extraction
• antioxidant activity
• foxtail millet bran
• total phenolic content