Food-grade phosphorylation enhances calcium binding in salmon peptides: Structural insights and bone health improvement for functional foods.

Phosphorylated salmon bone collagen peptides (P-CP) were developed via hydrolysis and food-grade sodium tripolyphosphate modification, resulting in a peptide-loaded phosphorus content of 334.3 mg/100 g, exhibiting high calcium-chelating capacity (91.21%). Structural analyses (FTIR, XRD, UV-Vis, fluorescence) confirmed phosphorylation and calcium chelation, with conformational changes enhancing mineral binding. Peptide omics analysis revealed that phosphorylation of CP might emphasize involvement of cellular calcium pathway-associated proteins. Proline, serine, and threonine frequently showed up around phosphorylation site within the peptide amino acid sequences. CP phosphorylation offered more calcium chelating site (oxygen in -PO32-) in binding with calcium chelation by ionic interaction. Through in vivo calcium-deficient mice, medium-dose of P-CP-Ca (133.34 Ca mg/kg) superiorly restored serum calcium levels, bone health-associated parameters. This study validates P-CP-Ca as sustainable bone health-improved substances derived from fishery byproducts for functional foods and supplements.