Synergistic modification of collagen structure using ionic liquid and ultrasound to promote the production of DPP-IV inhibitory peptides.

Abstract

Dual modification of collagen was performed using ionic liquid (IL) and ultrasound (US) to modulate the activity of collagen hydrolyzed peptides and reveal the production mechanism of cowhide-derived dipeptidyl peptidase (DPP-IV) inhibitory peptides. The results revealed that dual modification (IL + US) significantly improved the hydrolytic degree of collagen (P < 0.05). Meanwhile, IL and US tended to promote the break of hydrogen bonds, but inhibit the crosslinking between collagens. The double modification reduced the thermal stability and accelerated the exposure of tyrosine and phenylalanine of collagen, and improved the proportion of small molecular (< 1kDa) peptides in collagen hydrolysates. Interestingly, the hydrophobic amino acid residues and DPP-IV inhibitory activity of collagen peptides with small molecular weight (< 1kDa) was increased further under the combination of IL and US. Enhanced hypoglycemic activity of collagen peptides can be attained through the dual modification of IL and US. © 2023 Society of Chemical Industry.