Investigation into the potential of commercially available lesser mealworm (A. diaperinus) protein to serve as sources of peptides with DPP-IV inhibitory activity

Food-derived peptides are known to possess inhibitory activity against the dipeptidyl-peptidase IV (DPP-IV) enzyme, a target in the management of type 2 diabetes. While proteins from commonly consumed food commodities have been investigated as precursors of DPP-IV-inhibiting peptides, studies on novel protein sources, such as those from insects, are sparse. This research aimed to determine if DPP-IV inhibitors can be generated upon in vitro digestion or enzymatic hydrolysis of lesser mealworm protein isolate and concentrate. Treatment of the proteins with digestive enzymes and proteases generated hydrolysates with varying potency, thermolysin being the most effective at releasing active peptides (IC₅₀= 0.63 and 0.60 mg mL⁻¹ for the isolate and concentrate). Ultrafiltration of the thermolysin-treated hydrolysates did not significantly improve the potency. This study shows that DPP-IV inhibitors can be generated from lesser mealworm protein and provides insight on the potential of insects to serve as functional food ingredients.