Production of a novel black soldier fly larvae (Hermetia illucens) protein hydrolysate-zinc chelate: Characterization, chelation mechanism, and zinc solubility.

Zinc (Zn) is an essential trace element for humans and animals, meanwhile, as a novel raw material, the low-molecular-weight black soldier fly leave (BL) peptide can bind to Zn efficiently. The present study prepared a novel BL protein hydrolysate-Zn (BLPH-Zn) chelate to develop multifunctional Zn supplements. Briefly, the composition of BLPH was first analysed and 198 peptides were identified, among which 37 exhibited high predicted bioactivity including angiotensin-converting enzyme (ACE) inhibitory, dipeptidyl peptidase IV (DPP-IV) inhibitory, and antioxidant properties. The Zn chelation rate of BLPH-Zn was 52.96 ± 2.05% at the peptide-to-Zn mass ratio of 6:1, and cytotoxicity assays confirmed the safety of the chelate at concentrations up to 0.5 mg/mL. Zn binding induced a conformational rearrangement of BLPH, involving carboxy, amino, amide, and sulfhydryl groups. Moreover, BLPH-Zn exhibited a balanced amino acid composition, excellent antioxidant activity, and improved Zn solubility. All these results indicate that the BLPH-Zn can serve as a safe and multifunctional Zn supplement in functional zinc supplement industry.