Functional properties of cricket and grasshopper protein isolates

This study aimed to assess the extraction of protein isolates from crickets (CPI) and grasshoppers (GPI) and determine their techno-functional, physicochemical, and biofunctional properties. Defatting by solvent remission and supercritical fluid showed the highest efficiency (>90 % in both samples) compared to pressing and gravimetric defatting (<25 % in both samples). Combining alkaline-acid precipitation, sonication, heat treatment, and enzymatic hydrolysis of cricket and grasshopper supercritical fluid defatted flours generated CPI and GPI (95.67 % and 91.60 % protein content, respectively). Significant improvements (p < 0.05) were observed in the techno-functional properties of CPI and GPI, including emulsifying capacity (>45 % and 50 %, respectively) and foaming properties (33 % and 225 %, respectively). The physicochemical parameters of CPI and GPI protein isolates were improved, including clarification (brightness 30–33 %, hue intensity 14 %, and saturation 43 %), compressibility (Hausner ratio 5–28 %), and particle surface (74–89 %). CPI and GPI showed higher values (p < 0.05) of theoretical protein quality parameters and a higher antioxidant potential (ABTS, DPPH, iron chelation, and ORAC) in a range of 1.0–3.9-fold compared to raw flours. These findings emphasize improvements in the favorable techno-functional, physicochemical, and nutritional characteristics of edible insect protein isolates. CPI and GPI could represent environmentally friendly food ingredients that improve the nutritional value of foods.