Effects of Gamma Irradiation on Free Radical Components, Phenolic Content and Antioxidant Activity of Beebread

Abstract

Antiradical activity and free radicals before and after gamma-treatment of beebread were investigated by Electron Paramagnetic Resonance (EPR) spectroscopy. A narrow signal the intensity of which increased with the dose was assigned to O-centred free radicals induced by gamma rays. They are stable for 120 days after irradiation. The irradiation effect on antioxidant potential and content of phenolic compounds were studied. It was found that total phenolic and flavonoid content values increased after beebread irradiation depending on the dose. The antiradical activity of extracts was assessed by the DPPH free radical scavenging activity. The EPR study showed that it increased after irradiation with 5 kGy (27%) and 20 kGy (19%), while the slight decreasing (6%) was observed after irradiation at 10 kGy.