Antioxidant components and properties of buckwheat (Fagopyrum esculentum Moench) grain fractions

Abstract

Buckwheat (Fagopyrum esculentum Moench) is an alternative crop belonging to the Polygonaceae family. In comparison to antioxidant activity of frequently used cereals, buckwheat has been reported to possess higher antioxidant activity, mainly due to high rutin content. The objective of this work was to determine the main antioxidant compounds and antioxidant activity of buckwheat grain and fractions (wholegrain, hull and groat). Buckwheat grain fractions were extracted with ethanol/water (80/20, v/v), followed by determination of total phenolic content and DPPH radical scavenging activity. Determination of phenolic compounds and tocopherols was performed by HPLC. Significantly higher content of total phenolics was found in buckwheat hull than in wholegrain and groat. Protocatechuic acid, siringic acid, ferulic acid, sinapic acid, rutin and quercetin were quantified in all tested fractions, whereas vanilic acid was found in wholegrain and hull. The content of total tocopherols in investigated samples ranged from 9.95 μg/g for hull to 25.8 μg/g for groat. Hull was superior in scavenging activity on DPPH radicals as evidenced by its lower IC50 value. Obtained results can broaden the utilization of buckwheat, especially a share of hull in wholegrain flour production. Bakery products containing wholegrain buckwheat flour may be regarded as healthpromoting functional foods.