Antioxidant properties, element contents and antimicrobial activities of bee pollen collected by Apis mellifera L. in Türkiye

Aim of study: Recently, pollen has become a preferred nutritional supplement because of its complex composition. We examined the botanical origin, total phenolic/flavonoid content (TPC/TFC), antioxidant/antimicrobial activity, and element content of pollen samples collected from honeybees. This study also examined whether the elements contained in pollen, when consumed as food, posed a risk to human health. Area of study: Ten mixed pollen samples were randomly collected from honeybees in the apiaries of four different Turkish regions, which fall among the three phytogeographic regions of Türkiye. Material and methods: We evaluated total flavonoid (TFC) and phenolic (TPC) contents; antioxidant activities (radical scavenging activity, hydrogen peroxide scavenging activity - HPSA, ferric reducing antioxidant power - FRAP, and ferrous ion chelating activity - FICA), element concentrations and antimicrobial activity. Main results: According to the melissopalynological analysis, one sample was determined to be unifloral and nine samples were found to be multifloral. The values found ranged 271.42-601.85 mg GAE/100 g TPC, 23.53-34.50 mg CAE/100 g TFC, 22.19-23.78 μg/mL DPPH, 6.50-78.40 µg/mL ABTS, 20.43-150.94 μg/mL HPSA, 97.26-99.83% FRAP and 74.84-91.79% FICA. Rosmanic acid, p-coumaric acid, quercetin, apigenin, and naringin were identified in all samples, while catechin was detected only in S6 and S7. Element contents were found Mg > Fe > Mn > Zn > Cu > Se > Cr > Ni > Cd > Co. All the samples had high antibacterial activity against Bacillus cereus (MIC= 4.17-8.33 g/mL), and against Staphylococcus aureus (MIC= 8.33 g/mL), except S3 and S4. Research highlights: Different levels and combinations of these components are efficient in the antioxidant and antibacterial activity of pollen.