Comparison of the melissopalynological, antimicrobial and organoleptic composition of honey samples from Apis mellifera L. and Apis florea Gaertn. in Sudan

Abstract

Honey from Apis mellifera and Apis florea was collected from western and eastern regions of Sudan and investigated for quantitative/qualitative pollen analysis, organoleptic characterisation, and antibacterial analysis. Nearly 29 different pollen taxa belonging to 19 families were identified. Based on the frequencies determined: Leguminosae (≥ 10) was the dominant family, Poaceae and Amaranthaceae were sporadic (9–3) whereas Cyperaceae was rare (< 3). Herbs represented 52%, trees 38%, and shrubs 10%. Pollen from both cultivated and wild vegetation was identified. The taxa identified are angiospermous and no gymnospermous species were encountered. Four anemophilous pollen types were observed. Pollen of particular interests, such as Borassus aethiopum and Hyphaena thebaica, was also found. Calotropis procera and Leptadenia spp. were also observed in the current investigation; these pollen taxa are of infrequent occurrence in honey especially in Sudan and the nectar of these plants are claimed to contain poisonous substances. Pollen grains of the Combretaceae with a unique heterocolpate sculpture were found only, in Al Leeri representing a clear uniflorality of honeys in the area. The organoleptic analysis revealed statistically significant differences in pH (p ≤ 0.001), ash (p ≤ 0.03), sucrose (p ≤ 0.04), and electrical conductivity (p ≤ 0.05). Respectively, honey from A. florea had higher sodium (17.647, 6.753 mg/kg) and higher phosphorus (2.900, 2.080 mg/kg) than honey from A. mellifera. Whereas honey from A. mellifera, had higher manganese (0.218–0.151 mg/kg) than honey from A. florea, both honeys exhibited similar antibacterial potency against Staphylococcus aureus and Salmonella typhi.