Effect of storage conditions on antioxidant activity of bee pollen extracts

Bee pollen is a product of rich and varied chemical composition, and its biological activities are diverse. Many of these activities are related to the antioxidant effect of bee pollen. The aim of this study was to determine the effect of storage conditions on the antioxidant activity of bee pollen extracts. The study was conducted on three types of bee pollen extracts, namely, ethanol and pepsin extracts of bee pollen, as well as on ethanol extracts of pepsin-digested bee pollen. Antioxidant activity was determined by a DPPH method, directly after obtaining the extracts and after storing them for twelve months under various conditions, i.e. at -18 degrees C in the dark, at 4-8 degrees C in the dark, at room temperature in the dark, and at room temperature in the light. It was concluded that the 12-month storage of bee pollen extracts caused a decrease in the antioxidant activity of all extracts examined, and the decrease depended on storage conditions. The highest decrease in antioxidant activity was observed in all types of extracts stored at room temperature in the light. The lowest decrease in antioxidant activity was found in ethanol extracts of pepsin-digested bee pollen.