Protein quality evaluation in vivo of cricket flour (Gryllus assimilis) reared in Brazil

Abstract

This study aimed to evaluate the chemical and biological quality of Gryllus assimilis flour, through the analysis of nutritional and biochemical parameters of tests on young rats (Rattus norvegicus – Fischer). The most deficient essential amino acid was methionine, with a chemical score of 56.40%. For the net protein ratio (NPR) and net protein utilisation (NPU) ratio, the diet containing unsupplemented cricket flour was not enough to reach the NPR and NPU levels of the control group and was insufficient to promote weight gain in the rats. The addition of methionine and wheat bran increased the digestibility of the cricket flour, which resulted in a significant improvement in the levels of cricket protein utilisation, increasing the rates mentioned above and promoting weight gain in the rats. Based on our results, we can state that considering the age of the study animals, cricket meal was a sufficient source of protein for maintenance of body weight, but not for weight gain. Based on biochemical parameters (total protein, albumin, alanine transaminase, aspartate transaminase, creatinine, urea), the cricket meal did not compromise the general health of the study animals. We therefore conclude that the addition of other sources of methionine to cricket flour can be a fundamental strategy for better use of cricket proteins in the diet.