INFLUENCE OF BOTANICAL ORIGIN ON PHENOLIC CONTENT AND ANTIOXIDANT CAPACITY OF MONOFLORAL BEE POLLEN

Background. Bee pollen, a source of nutrients for adult honey bees and larvae, is produced from plant flower pollen which bees collect and mix with nectar or secretions from their salivary glands. Bee pollen contains nutritionally essential substances like proteins, lipids, amino acids, mineral substances, and vitamins but also carotenoids, flavonoids, and polyphenols. The amount of each substance contained in bee pollen depends on the botanical origin and the source region. Recently, many investigations have been concerned with the antioxidant properties of different food products. The aim of this research was to examine the antioxidant capacity of bee pollen and investigate its relationship with total phenolic and flavonoid contents. Materials and methods. Samples were collected from three locations in Croatia from April to June 2019. Sixteen bee pollen pooled samples were classified according to color and, after melissopalynological analysis, total phenolic (Folin-Ciocalteu method) and total flavonoid contents and antioxidant capacity (FRAP assay) were determined in fourteen monofloral bee pollen samples. Results. The monofloral bee pollen samples had 82-100% of their pollen originating from one botanical species. The highest total phenolic content (TPC) was measured in Prunus spp. and Salix spp. monofloral bee pollens (15.80 and 13.75 mg GAE/g, respectively), which also had the highest ferric reducing-antioxidant power (FRAP) values (124.44 and 147.61 mu mol Fe2+/g, respectively). The samples with the lowest TPC (Crepis biennis L. and Taraxacum officinale F.H. Wigg. ; 4.00 and 5.34 mg GAE/g, respectively) also had the lowest FRAP values (25.24 and 34.74 mu mol Fe2+/g, respectively). The values for total flavonoid content (TFC) did not vary a lot between the analyzed samples (5.05-9.71 mg QE/g). Conclusion. In comparison to some other food products, bee pollen, like most bee products, appears to be a good source of antioxidants. The botanical family or botanical species of bee pollen affects the antioxidant properties of the bee pollen. Due to a lack of research on monofloral bee pollen in comparison to pooled samples, knowledge about specific parameters of different monofloral bee pollen samples should be broadened.