Antioxidant and radical-scavenging activities of buckwheat seed components

The search for endogenous components in food ingredients exhibiting antioxidant activity has been intensified in order to eliminate synthetic antioxidants. Tocopherols are widely used as natural antioxidants, although their protective ability is not always sufficient. Buckwheat seed components were evaluated for antioxidant and free radical-scavenging activities using solvents of different polarities to isolate components from hulls and greats. Components extracted from buckwheat hulls were pro-oxidant in canola oil. Antioxidant activity of extracts from buckwheat greats increased when more polar solvents were used for extraction. The highest activity was observed for the methanolic extract. Radical-scavenging activity of buckwheat extracts was analyzed with DPPH (2,2-diphenyl-2-picryl-hydrazyl). This activity increased when the more polar solvents were used for extraction, with the highest activity observed for the methanolic extract. It was also observed that the radical scavenging effectiveness of extracts was concentration dependent. Analysis revealed the presence of tocopherels in the hexane extract, while methanolic extracts were rich in phenolic acids and flavonoids.