Storage methods, phenolic composition, and bioactive properties of Apis mellifera and Trigona spinipes pollen

Abstract

The aim of this study was to evaluate the influence of lyophilization and drying in stove on phenolic compounds content and the biological activity of Apis mellifera and Trigona spinipes pollens produced in Brazil. In general, the bee pollen produced by T. spinipes presented highest antioxidant activity in dried and fresh samples assessed either by test of plasma ferric reduction capacity (FRAP) and free radical scavenging assay (DPPH) methods. For A. mellifera bee pollen the antioxidant activity was higher on the fresh samples. Nevertheless, β-carotene bleaching assay (BCB) and linoleic acid content were higher in T. spinipes samples, mainly in the fresh ones. Higher antioxidant activity was owing to higher content in phenolic compounds. Lyophilization method was the best for phenolic compounds’ conservation for both species. The bee pollen of both species has a high amount of flavonoids: kaempferol-3-O-glucoside was the most abundant in A. mellifera while for T. spinipes the most prevalent was resorcylic acid + epicatechin. All extracts presented antibacterial activity against Saphylococcus aureus (ATCC 43300)™, (ESA 83138150), (ESA 32), Pseudomonas aeruginosa (ATCC 15442)™, Pseudomonas aeruginosa (MRC.4) and (MRC.10). The methods used for storage influenced the biological properties of bee pollen from both species. Regarding the content of phenolic compounds, differences were observed amongst the pollen types: for A. mellifera these were best preserved with lyophilization, while for T. spinipes the three storage methods were equivalent.