Preparation of cattle bone collagen peptides-calcium chelate and its structural characterization and stability

In this study, cattle bone collagen peptides (CPs) were applied to prepare peptides-calcium chelate (CPs-Ca), and the physicochemical, structural properties, and stability of the CPs-Ca were characterized. The optimized preparation conditions were determined by single factor test, and the maximum calcium-chelating capacity was 42.70 ± 1.09 μg/mg. Physicochemical analysis indicated that CPs-Ca was a new substance compared with CPs. Structural analysis demonstrated that calcium ions chelated CPs via the sites of carboxyl oxygen, hydroxyl oxygen and amino nitrogen atom. Morphology analysis showed that CPs-Ca aggregated to large particles due to the crosslinking of calcium ions. According to the stability analysis, CPs-Ca was stable in thermal processing and gastrointestinal digestion. The acid environment was the major factor of CPs-Ca dissociation. The findings put forward a scientific basis for preparing a novel calcium supplement and high-value utilization of cattle bone.