Protein and phenolic content and antioxidant capacity of honey bee-collected unifloral pollen pellets from Finland

Protein and phenolic compound content and antioxidant capacity were determined from honey bee collected unifloral pollen pellets from Ranunculus, Brassica, Filipendula, Rubus, Vicia, Trifolium, Epilobium, and Taraxacum species of boreal coniferous zone in Finland. The aim of the study was to investigate the relation between the chemical composition and the botanical origin of the pollen pellets. The protein content of pollen pellets ranged between 18.2 and 29.3%. One hundred and twenty phenolic components were detected from the samples and their total amount was highest in Brassica and the lowest in Taraxacum pollen pellets. Cinnamic acid content was high in Brassica and T. repens compared to other species. Most of the flavonoids in pollen pellets were flavonols, which were highest in Ranunculus, Filipendula and Epilobium originated pollen pellets. The pollen pellets of Ranunculus, Brassica, Filipendula, and T. repens had an antioxidant activity of over 80%. The lowest activities, about 40%, were measured in Taraxacum and Epilobium samples.