Protein quality evaluationin 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.

Caracterização nutricional de farinhas de insetos com potencial de utilização na alimentação humana

“…Net protein ratio (NPR) is determined taking into account the average weight gain of the animals in the test group, weight loss of the animals fed the non-protein diet and the average protein intake. In three studies, no NPR differences were observed between animals that consumed casein and animals in the test groups [12][13][14] Araujo et al, (2020) [15] , found lower NPR values for animals fed with insects.…”

“…Regarding the animal model used in the studies, most used rats (n=9; 90%) [6,[9][10][11][12][13][14][15][16] . Only one study was carried out with mice (n=1; 10%) [17] .…”

“…Only one study was carried out with mice (n=1; 10%) [17] . Most studies used male animals (n=9; 90%) [6,[9][10][11][12][13][14][15][16] , and only one study (10%) was carried out with mice of both sexes [17] . The main characteristics of the studies were chronologically organized by year of publication, starting from the first published article.…”

“…Four studies included in this systematic review found no differences in weight or body weight gain between the animals in the control group that received casein and the animals that received insects as a source of protein in the diet [6,9,12,17] . In contrast, two studies reported less weight gain in the test group [15,16] , and one study observed that the control diet allowed better results for animal growth performance, as highlighted by the higher daily weight gain and the lower feed conversion ratio [11] . Thus, animals fed Acheta domesticus and Tenebrio molitor presented lower growth performance rate [11] .…”

“…In the experiment by Choi et al ( 2020) [9] , food intake of the test group was higher than that of the control group. However, most studies have not reported significant differences in food consumption between insect-fed and standard diet groups [12,15,17] , while Ekpo (2011) [16] observed lower feed consumption among rats fed diets composed of Oryctes rhinoceros, Imbrasia belina, and Macrotermes bellicosus.…”