Physicochemical properties, sugar analysis, antioxidants, and antibacterial activity of Plebeina armata honey from Western Tanzania

Stingless bee honey is one of the prized natural products in the tropics where it is widely used for food and medicine. While the domestication of stingless bees and the scientific study of their products continue to evolve, there is still little progress for ground-nesting stingless bees. This study investigated chemical and biological properties of honey produced by Plebeina armata, a ground nesting stingless bee native to the African tropics. Eight honey samples were collected from natural colonies of P. armata from four different locations in western Tanzania. Physicochemical properties were analyzed using standard methods, and the concentrations of fructose, glucose and sucrose were determined by high performance liquid chromatography (HPLC). Total flavonoid content (TFC), total phenolic content (TPC) and DPPH radical scavenging activity (RSA) were assayed to determine the antioxidant capacity of the honey samples. Finally, broth microdilution assay was conducted to determine the minimum inhibitory concentrations (MIC) of the samples against reference strains: Staphylococcus aureus ATCC 25923, Bacillus spizizenii ATCC 14028 and Salmonella enterica Typhimurium ATCC 6539. The results showed diverse physicochemical and sugar profiles with significant variations across the honey samples. The levels of TFC (30.55–93.7 mg QE/100 g), TPC (74.07–177.28 mg GAE/100 g) and RSA (42.61–82.65%) revealed substantial antioxidant potential. Additionally, MIC values ranged from 2.5 to 10% w/v indicating strong antibacterial potency. These findings highlight the chemical complexity and therapeutic potential of Plebeina armata honey, providing essential information to enhance awareness of this product, and promoting sustainable practices in its production.