Antioxidant activities of buckwheat extracts

摘要

The antioxidant activities of buckwheat (Fagopyrum esculentum Moench) extracts were evaluated and compared with butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tertiary butylhydroquinone (TBHQ) using a β-carotene bleaching assay, a 2,2-diphenyl-β-picrylhydrazyl (DPPH) assay and the Rancimat method. Buckwheat was extracted with solvents of different polarities. The methanol extract showed the highest antioxidant activity coefficient (AAC) of 627 +- 40.0 at 200 mg/l by the β-carotene bleaching method and longest induction time of 7.0 +-0.2 h by the Rancimat method. The acetone extract showed the highest total phenolics of 3.4 +-0.1 g catechin equivalents/100 g and the highest scavenging activity of 78.6 +-6.2% at 0.1 mg/ml by the DPPH method. The properties of the extracting solvents significantly affected the yield, total phenolics and antioxidant activity of buckwheat extract.