ABSTRACT

Peptides produced by hydrolysis of milk proteins during technological processes and storage greatly influence the functional and biological properties of dairy products. This chapter deals with the main analytical techniques for milk peptide analysis. The first section deals with the conventional methods for peptide separation, detection and quantification, such as electrophoretic and chromatographic methods, as well as spectroscopic and immunochemical techniques. The second section pays special attention to mass spectrometry (MS) because its application to milk peptides has grown enormously during the past decades, becoming a key tool in this area. A brief survey of the most commonly used ionisation techniques (electrospray and matrix-assisted laser desorption/ionisation) and mass analysers is included. Finally, the application of this technique to dairy products and specifically to milk proteomics, evaluation of proteolysis in cheese and processed milk and quantitative analysis is illustrated using several examples.