Buckwheat - the source of antioxidant activity in functional foods

Antioxidant activities of buckwheat seeds, dehulled seeds, hulls, straws and leaves were evaluated and compared with those of oats and barley. Schaal oven test at 70 degreesC with gravimetric indication and lard as the substrate was applied. Protection factors ranged from 1.3 to 8.0 and increased in the order: buckwheat straws < buckwheat hulls oats < barley < buckwheat seeds < buckwheat dehulled seeds < buckwheat leaves. Methanol extract of buckwheat seeds showed higher antioxidant activity in comparison with petrolether extract, protection factors amounted to 2.9 and 1.9, respectively Total phenolics, rutin and tocol contents in tested samples were determined and related to the antioxidant activities. Statistically significant relationship between total phenolics content as well as rutin content and antioxidant activity of buckwheat material was observed (R-2 = 0.987, P < 0.002, R-2 = 0.972, P < 0.002, respectively) Significant correlation between tocol content and antioxidant activity was not found. (C) 2002 Published by Elsevier Science Ltd.