The effect of processing on the protein quality of four popular insects consumed in Southern Nigeria was carried out in the study. A crude protein content (% wet weight) of 35.18 ± 0.10, 8.38 ± 0.31, 11.76 ± 0.90 and 33.41 ± 0.20 were obtained for IBL (Imbrasia belina), RP (Rhynchophorus pheonicis), OR (Oryctes rhinoceros) and MB (Macrotermes belicosus) respectively. These values on a dry weight basis were higher when compared with most conventional protein sources. Amino acid analysis revealed that the proteins contained all the essential amino acids, especially lysine, threonine and methionine which are the major limiting amino acids in the cereal and legume based diets. Biological assays, using weanling, male albino rats, suggested high nutritional and toxicological safety of the insects. The PER for OR, MB, and RP (% of casein) ranged from 94 -111 while IBL values were lower (51 – 71). The TD and BV for all the insects were not significantly different from the control (P ≥ 0.05), though boiling increased the BV of the proteins with the exception of value for raw IBL. The relative weights (g/kg live weight) of the liver, spleen, heart, kidney and lungs were significantly different for IBL only, but the rat serum enzyme activities for the boiled and fried insects showed no significant difference from the control (P≥ 0.05). Processing generally was observed to improve the biological parameters assayed for in the experiment. These results suggest these insects as good sources of essential nutrients which could go a long way in helping to solve most nutritional problems among the populations that consume them.
