General test method in salt industry-Determination of calcium and magnesium ions
What they found was a mixture of proteins, some positively charged and some negatively charged, and a lot of calcium and magnesium ions.
Calcium is present in casein micelles as bound calcium ions and as colloidal calcium phosphate (see Salts); sodium, potassium and magnesium ions are also bound to protein in the micelle together l amounts of citrate.