Effect of HHP, Enzymes and Gelatin on Physicochemical Factors of Gels Made by Using Protein Isolated from Common Cricket (Acheta domesticus)

The effect of high hydrostatic pressure (HHP) combined with enzymatic methods or gelatin incorporation in the gelation process of protein isolated from Acheta domesticus was investigated. The results indicate that transglutaminase (TGasa) or glucose oxidase (GOx) enzymes can induce reversible aggregation in dispersions of insoluble protein fractions and increase viscosity in dispersions of soluble fractions, but does not induce gel formation even after HHP treatment; in consequence, enzymatic treatment on cricket protein can be used to increase viscosity but not to form gels. It is technically feasible to obtain gels by adding 2% porcine gelatin to dispersions of protein fractions and subjecting them to HHP. The firmness and syneresis variation values of those gels during storage depended on the protein extracted fraction (insoluble or soluble protein) and on the concentration of protein used. The highest hardness and lowest syneresis was found with the gels obtained from the insoluble fraction at 11 and 15% (w/w) protein concentration. Color difference (ΔE* > 3) appreciable to the naked eye was observed along the storage period and no noticeable pH variations were found after 28 days of storage. Results indicate that new raw materials of interest can be developed for the food industry based on cricket protein isolates, to make high-protein foods which could be applied in a wide variety of different food applications including 3D printing or fat substitution.