Preparation, Characterization, and In Vitro Stability Analysis of Deer Sinew Peptide-Zinc Chelate

Novel peptide-zinc chelates (DSPs-Zn) with a zinc content of 186.94 mg/g were synthesized from deer tendon peptides at pH 6, 60 °C, 60 min, and peptide-zinc mass ratio of 1:3. Ultraviolet-visible absorption spectroscopy (UV) and Fourier transform infrared spectroscopy (FTIR) demonstrated that the chelation sites of the deer tendon polypeptides (DSPs) with zinc ions were located at the carboxyl oxygen and amino nitrogen atoms of the peptides. Amino acid analysis showed that aspartic acid, glutamic acid, lysine, and arginine play important roles in the chelation process. In vitro simulated gastrointestinal digestion studies showed that DSPs-zinc exhibited higher stability than zinc sulfate and zinc gluconate in the pH range 2-8 and in a simulated gastrointestinal digestion environment. The above experimental results suggest that DSPs-Zn has the potential to be used as a novel zinc nutritional supplement.