ABSTRACT
Electron microscopy and physicochemical analysis show that proteins in human milk are present either in micelles, bound to the milk fat globule membrane (MFGM) or in soluble form in the whey fraction. The micelles, which give milk its white appearance, incorporate particular proteins, the caseins, and mineral ions, mainly calcium, phosphorus, and magnesium. Neither the composition nor function(s) of protein bound to the MFGM (about 1% is well understood (see Chapter 8). The remaining proteins, known as “soluble proteins” or whey proteins (see Chapter 3), are in true solution.
