Nutrient Composition, Mineral Analysis and Anti-nutrient Factors of Oryctes rhinoceros L. (Scarabaeidae: Coleoptera) and Winged Termites, Marcrotermes nigeriensis Sjostedt. (Termitidae: Isoptera)

Abstract

Introduction: The palm beetles, Oryctes rhinoceros L. (Scarabaeidae: Coleoptera) and Termites, Macrotermes nigeriensis Sjostedt, (Termitidae: Isoptera) are prominent edible insects in Nigeria. Aim: Nutrient analyses were carried out on the winged reproductive termites, M. nigeriensis and the larvae of palm beetles, O. rhinoceros to determine the nutrient composition, mineral composition and the antinutrient / secondary metabolites composition of the two insects. Methods: The insects were collected from the campus of Ekiti State University Ado-Ekiti, and taken to the laboratory where they were oven-dried at 60º for 4 h. The proximate, mineral and antinutrient/secondary metabolites compositions were determined using official methods of analyses of AOAC (Association of Official Analytical Chemists) and atomic absorption spectrophotometric respectively. Results: Results show that M. nigeriensis and O. rhinoceros are full of nutrients and minerals that are vital to health. M. nigeriensis contained 4.52% moisture content while O. rhinoceros had 5.42%. Ash content was 3.24% in M. nigeriensis while O. rhinoceros had 11.83%. The protein, fat, fibre and carbohydrate contents of M. nigeriensis are 37.54%, 48.03%, 5% and 2.06% respectively. In O. rhinoceros, the protein, fat, fibre and carbohydrate contents are 52%, 10.84%, 17.94% and 1.97% respectively. All the important mineral salts were present in both insects. Iron (Fe) was present at levels that commensurate with the daily recommended allowance (8.57 mg/00 g – 10.59 m/100 g) in O. rhinoceros and M. nigeriensis respectively. Phosphorus was highest in M. nigeriensis with a value of 103.47 mg/100 g. This mineral was followed in value by potassium (27.57 mg/100 g and the least was copper (0.01 mg/100 g). Lead (Pb) was not detected in any of the insects. In O. rhinoceros, phosphorus (75.57 mg/100 g) was highest, followed by potassium (25.44 mg/100 g) and the least was copper (0.01 mg/100 g). The levels of antinutrient/secondary metabolites are so insignificant to cause any problem. Conclusion: M. nigeriensis and O. rhinoceros are nutrient-rich insects that can supply adequate quantities of the various classes of food to animals. The insects are also rich in minerals which are important for the normal development of the body. The levels at which antinutrient / secondary metabolites occur is not a threat to animals that feed on these two insects.