Assessment of nutritional resources quality from honeybees (Apis mellifera adansonii, L. 1758: Hymenoptera, Apidae) in three beekeeping sites of the Democratic Republic of Congo

Abstract

Food products from honeybees are commonly used in Africa as in other parts of the world. The composition of bee related food is important for consumers but also to illustrate the feeding quality for the bees. The present study was aimed at assessing the quality of bee bread and honeys for the survival of A. mellifera adansonii, L. 1758 in the DRC. Several environments were selected, namely a rainforest in Kisangani, a savannah in Kavwaya and a restored forest in Mampu. Bee breads were assessed according to their richness in proteins and essential amino acids. Honeys were evaluated considering the water content, the sugar rates, the amount of 5-(hydroxymethyl)-2-furaldehyde (HMF), the acidity (pH) and conductivity. The average content of protein from pollens collected in the DRC was 14.11 ± 5.27%. The protein content was low compared with the food needs of bees (and to the European breeds). No significant difference was observed between Kisangani, Mampu and Kavwaya in terms of protein content of beebread (P ≥ 0.05). The concentrations of ten essential amino acids for bees were within the optimum range of food needs for honeybees (set for European bee races). Beebreads collected in the rainforest of Kisangani were significantly richer in isoleucine, leucine, valine, arginine, lysine and phenylalanine than those from the savannah of Kavwaya. However, beebreads harvested in Kisangani were not significantly different from those from the replanted Mampu forest. The analysis of honey samples revealed that the Congolese honeys had good nutritional quality for bees. Indeed, reducing sugar content of the collected samples ranged from 63.40 to 73.80%, the content of sucrose ranged from 0.30 to 1.90%, the content of water varied from 16.80 to 22.00%, the pH of the analyzed honey samples ranged from 4.22 to 4.53. The average of the electrical conductivity was 47.74 ± 13.93 μS/cm and the concentration of HMF varied from 1.75 to 31.38 mg HMF/kg of honey. The honeys collected in the rainforest of Kisangani were significantly richer in minerals and moisture than those from the savannah of Kavwaya (P <0.05). However, the honeys collected in the last savannah were richer in sucrose and HMF than those collected in the Kisangani rainforest and the restored forest of Mampu (P <0.05). These results would only be applied for the time at which the samples were collected (January-February) but are an interesting data set for further use of bee related product in DRC.

Keywords: Apis mellifera adansonii, honey, bee bread, quality, nutrition, bee ecology, DRC.