Cricket isolates as ingredients to design protein foods: Functional, structural and interfacial properties

Abstract

The ever-increasing world population has led to an increased demand for protein-rich food. This promoted continuous research on new types of suitable proteins with good amino acid profiles. This work evaluated the functional and interfacial properties of a commercial cricket (Acheta Domesticus) protein flour (69.4 %w/w of proteins). The raw meal was defatted with supercritical CO₂ and hexane extraction. Both methods proved to be effective, with a similar extraction yield (close to 80 %). Protein solutions were prepared by solubilizing either the raw or the defatted meal in bi-distilled water and they were used to evaluate the isoelectric point (ranging between pH 4 and 4.4), solubility (the highest value, i.e., 80 % was observed close to pH 11) and interfacial properties. Using the pendant drop method, interfacial tension was evaluated at the air/water and water/oil interface. The measurements at both interfaces showed a significant decrease in tension values, due to the protein adsorption. The adsorption isotherms at both interfaces exhibited a typical sigmoidal trend with values close to those of typical animal proteins. Finally, the foaming (FC) and emulsifying capacities (EC) were measured obtaining, at 10 % w/w of protein content, results interesting for potential practical uses.