EXAMINATION OF ANTIOXIDANT CAPACITY OF BEEBREAD EXTRACTS BY DIFFERENT COMPLEMENTARY ASSAYS

Abstract

Total phenolic and flavonoid content were measured in different solvent extracts of beebread, as well as their antioxidant capacity. The content of total polyphenols was quantified according to the Folin-Ciocalteau method. The flavonoid estimation was made using two complementary colorimetric methods, using both aluminum chloride reaction (according to a modified Dowd method) and 2, 4-dinitrophenylhydrazine. The samples content varied between 22.72- 8.32 mg GAE g-1 (total phenols), 0.696-0.168 mg QE g-1 (flavonols, flavones and isoflavones) respectively 7.86-3.12 mg NAE g-1 (total flavanones). The antioxidant capacity was determined by free radical scavenging (DPPH 2,2-diphenyl-picrylhydrazyl) method, by ferric reducing antioxidant power (FRAP) and by ABTS (3-ethyl-benzothiazoline-6-sulfonic acid) assays. Good correspondences between the antioxidant activity and the content of total phenols and flavonoids of beebread extracts were found.