Identification of adulteration in water buffalo mozzarella and in ewe cheese by using whey proteins as biomarkers and matrix-assisted laser desorption/ionization mass spectrometry.

A rapid and accurate method to identify bovine and ewe milk adulteration of fresh water buffalo mozzarella cheese by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) is described. The differentiation among mozzarella made from water buffalo milk and from mixtures of less expensive bovine and, more recently, ewe milk with water buffalo milk is achieved using whey proteins, alpha-lactalbumin and beta-lactoglobulins as molecular markers. It is worth noting that the method proposed here is, to our knowledge, the first strategy able to characterize possible fraudulent additions of ewe milk in samples of water buffalo milk devoted to the production of water buffalo mozzarella cheese. In addition, a linear relationship was found between the relative response of the molecular ion and the abundance of the analysed whey proteins. This demonstrates that this approach can be used to determine the amount of bovine or ovine milk added to water buffalo milk employed for mozzarella cheese production. Furthermore, this method also appears suitable for the analysis of ewe cheese. Hence these findings open the way to a new field for mass spectrometry in the evaluation of possible fraudulence in dairy industry production. Copyright 2002 John Wiley & Sons, Ltd.