Journal of Food: Microbiology, Safety & Hygiene
Open Access

Abstract

Nutritional Composition and Microbiology of Some Edible Insects Commonly Eaten in Africa, Hurdles and Future Prospects: A Critical Review

Amadi EN and Kiin-Kabari DB

An overview of the microbiology and nutritional composition of eight (8) insects, Bunaea alcinoe, Rhynchophorus phoenicis, Gonimbrasia belina, Gryllotalpa africana, Cirina forda, Brachytrupes membranaceus, Macrotermes natalensis, and Anaphe venata used as food is presented. All the edible insects whose microbiological flora is known have mixed population of bacteria with Bacillus and Staphylococcus persistently occurring. The Gram-negative population is more diverse and included members of the genera, Acinetobacter, Enterobacter, Klebsiella, Proteus, Pseudomonas and Serratia. Available data show that edible insects contain protein concentrations ranging from 22.06 to 74.35% (Lepidoptera (≥ 38+ to 74.35%), Coleoptera larva (22.06 to 30.30%), Coleoptera adult (26.85 to 32.71%), Isoptera (35.06%) and Orthoptera (65.62%). The larval forms seem to have a high fat content compared to the adult forms. The ten essential amino acids are present in varying amounts while the major fatty acids are palmitic, oleic and linoleic, which is highly unsaturated. Different species of Rhynchophorus species may have different quantities of amino acids or indeed, domestication may affect the quantities of amino acids of Rhynchophorus species. The major fatty acids (occurring at more than 10%) of R. phoenicis (Coleoptera) are palmitic acid, oleic acid and linoleic acid while those of G. belina and C. forda (Lepidoptera) are palmitic, oleic, linoleic and stearic acids. Macro-elements and micro-elements of R. phoenicis occur at significant amounts. Iron and magnesium occur in the order, Coleoptera, more than in Isoptera, Lepidoptera and Orthoptera. There seems to be a dearth of information on the macro- and micro-elements, amino acid and fatty acid compositions of some insects. A more comprehensive, standardised and universally acceptable method for estimating proximate composition of edible insects is advocated so that values obtained can be scientifically compared. Further work on comprehensive nutritional studies and microbiological flora of edible insects and insect husbandry/farming are also advocated.