Preparation, characterization and antioxidant effect of polypeptide mineral-chelate from Yanbian cattle bone

In this study, Yanbian cattle bone albumin polypeptide (AP) and globulin polypeptide (GP) were combined with minerals (calcium and iron) to prepare polypeptide chelates, respectively, and the chelates were characterized. The hydrolysis degree of AP was 33.1%, and GP was 18.8% by a single-factor test. The maximum mineral-chelating capacities of the albumin polypeptide chelating calcium (AP-Ca), albumin polypeptide chelating iron (AP-Fe), globulin polypeptide chelating calcium (GP-Ca), and globulin polypeptide chelating iron (GP-Fe) were 27.7%, 34.8%, 24.8%, and 29.9%, respectively. The results showed calcium and iron ions chelated the polypeptide through the carboxyl, carbonyl, and amino groups. The nutritional value of the amino acids after chelation was similar to that before. The structures of AP-Fe and GP-Fe were denser than those of AP-Ca and GP-Ca, and spherical calcium crystals and iron crystals were on the surface. The particle size before chelation was smaller than that after chelation. The antioxidant activity of the polypeptide mineral chelate was improved compared with that before chelation. The antioxidant activity of chelated iron was higher than that of chelated calcium, and the antioxidant activity of GP-Fe was higher than that of AP-Fe. In conclusion, the AP and GP of Yanbian cattle bone had a good chelation degree with calcium and iron ions and had specific antioxidant activity. These findings suggest a high-value utilization of Yanbian cattle bone.