MALDI-ToF MS for quality control of high protein content sport supplements

High protein content sport nutritional supplements are found as powder products containing, asingredients, amino acids and proteins with important nutritional values as milk, soy and egg proteins.An EU Food Supplements Directive (2002) requires that supplements should be safe, both in dosagesand in purity. It is important, then, to develop rapid and sensitive methods to be employed for the qualitycontrol of these substances. In this work, we apply, for the first time, matrix-assisted laser desorptionionization-mass spectrometry as a fast, reproducible and sensitive method for the quality control of sportnutritional supplements based on proteins.To this aim, several commercial egg- and/or milk-based powder products have been processed by in gelor in solution digestion and analyzed in comparison to pure standard products. This strategy allowed toassess the reliability of the indications on proteins (as caseins, whey proteins and ovalbumin) declared inthe label of several sport nutritional supplements.