Effect of microwave-assisted enzymatic hydrolysis of cricket (Gryllodes sigillatus) protein on ACE and DPP-IV inhibition and tropomyosin-IgG binding

Techniques, such as microwave-assisted enzymatic hydrolysis, provide options to generate insect-bioactive peptides. However, allergenicity of these novel bioactive peptides remains a concern. Cricket protein was enzymatically hydrolyzed using conventional heating or microwave radiation. Protein hydrolysates were evaluated for DPP-IV and ACE inhibition activity, and tropomyosin-IgG reactivity (a major cricket allergen). ACE and DPPIV inhibition was highest in the microwave-hydrolyzed protein (IC50 = 0.096 mg/ml and 0.27 mg/ml, respectively). All samples displayed tropomyosin-IgG reactivity; however, the lowest binding was obtained with the microwave-hydrolyzed protein. Raman spectroscopy revealed conformational changes, particularly in the Amide I and S-S regions, which may correlate to the observations in the immunochemical reactivity. In conclusion, microwave-assisted enzymatic hydrolysis can be a useful method for generating bioactive peptides from insect proteins and lowering their immunoreactivity, validating the potential of these treatments to generate bioactive, hypoallergenic peptides for food and pharmaceutical applications.