Matrix-assisted laser desorption/ionization mass spectrometry in evaluation of protein profiles of infant formulae

Breast-feeding is the nutritional model in humans, and is continued after birth for variable periods. Milk represents an essential source of growth from both nutritional and functional points of view. When nursing is not possible, indicated or sufficient, artificial feeding becomes essential. Substitutes for mother's milk are usually obtained by modifying the composition of cow's milk either qualitatively or quantitatively. The changes usually involve enzymatic and/or thermal treatment, and for this reason a description of the protein profiles of milk formulae is of great interest. After examination of the results obtained by matrix-assisted laser desorption/ionization (MALDI) in the characterization of protein profiles of cow's milk after different thermal treatments, the application of this analytical technique in the above context appeared interesting. MALDI data for eleven milk formulae, directly acquired from the market, are described and discussed. Results indicate that MALDI mass spectrometry is a particularly powerful method which may be employed either during the production stages of milk formulae or to study the relationships between milk protein content and clinical formula evaluation.