EFFECT OF BLANCHING AND DRYING METHOD ON CRICKET PROTEIN PROPERTIES

Edible insects have been considered as one of the key solutions to the growing demand for animal protein because they are a rich source of good quality protein and have a lower environmental impact compared to the traditional livestock. There are few studies on the impact of processing techniques on insect’s protein. Thus, the aim of this work was to evaluate the effect of blanching and drying method on the properties of cricket protein. Adult crickets (Gryllus assimilis) were fastened for 24 h and slaughtered by freezing. Three treatments were performed: F.D. = freeze-drying (-55 ºC, ~60 μHg, 48 h); B.F.D. = blanching (10 min in boiling water) and freeze-drying; B.O.D. = blanching and oven-drying (65 ºC, 20 h). After the treatments, the dried crickets were ground and protein content, protein solubility, water and oil holding capacities were analyzed. Protein content did not differ among treatments (59-61%). Protein solubility was evaluated in pH values 3, 7, and 10. The protein solubility was maximum in pH 10 and minimum in pH 7. Regardless the pH, F.D. showed the highest protein solubility (28-50%), while B.O.D. the lowest (9-17%). Water holding capacity ranged from 2.4 to 3.5 g of water/g of sample, while oil holding capacity ranged from 2.3 to 2.9 g of oil/g of sample, with B.F.D. presenting the highest values. In conclusion, the treatments of blanching and oven-drying caused a reduction in protein solubility, while blanching treatment had a positive effect on water holding and oil holding capacities.