Abstract：To improve the comprehensive utilization of horse slaughter and processing by-products, horse bone marrow collagen was hydrolyzed with different proteases for the preparation of calcium-chelating peptides using calcium gluconate as the calcium source, whose functional properties were evaluated. Protein content was determined by the BCA assay, structural characterization was performed by ultraviolet (UV) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM), and in vitro antioxidant activity was tested. The results showed that the calciumchelating peptide prepared using pepsin had the highest protein content (39.97%). The UV and FTIR spectra of both the peptides and calcium-chelating peptides exhibited characteristic absorption peaks. SEM showed that calcium-chelating peptides formed a dense structure with a rough surface composed of accumulated particles. The element analysis showed that the peptides prepared using alkaline and neutral proteases had a strong affinity for calcium. The half maximal inhibitory concentration of the calcium-chelating peptides prepared using alkaline and neutral proteases, papain and pepsin were 0.21, 1.20, 0.56, and 0.23 mg/mL for scavenging capacity of 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical, and 0.96, 2.04, 1.27, and 0.48 mg/mL for ferrous ion chelating capacity, respectively. The calcium-chelating peptide obtained using pepsin had the highest oil-holding capacity (38.07 g/g), while that obtained using alkaline protease had the highest water absorption capacity (5.82 mL/g) and emulsifying activity index (1.56 m2/g). In conclusion, calcium chelating can increase the calcium content of horse bone marrow collagen-derived peptides while improving their antioxidant activity and physicochemical properties.
2025, Vol. 39 
