Micellar calcium phosphate-cross-linkage in buffalo casein micelles

The composition of buffalo casein micelles and the physico-chemical properties of micellar calcium phosphate (MCP)-cross-linked casein in buffalo casein micelles were investigated. Micellar casein content was 3.84% in buffalo milk, which was higher than that of bovine milk. The total calcium, micellar calcium, and inorganic phosphorus (Pi) contents were also higher in buffalo milk than in bovine milk. In buffalo milk, micellar calcium and Pi contents were 214.9 and 103.3 mg/100ml, respectively, which were higher than those of bovine milk. The MCP-cross-linked casein in buffalo casein micelles, which was separated from buffalo casein micelles by high-performance gel chromatography on a TSK-GEL G4000SWXL column using 6 M urea-simulated milk ultrafiltrate as the eluent, was 63.46% of total casein content, which was higher than that of the corresponding casein micelles of bovine milk. The serum casein content increased when buffalo milk was cooled at 4 degrees C for 24 h. The higher concentrations of micellar Pi and calcium were considered to be possibly responsible for the more MCP-cross-linked casein in buffalo milk.