In addition to its major nutritional role, the bioactive potential of milk is now well accepted. It has been recognised that much of the bioactivity can be attributed not only to intact caseins and whey proteins but also to many milk protein-derived peptides (Korhonen, 2009). Such peptides are inactive within the sequence of the parent protein and can be released by digestive enzymes during gastrointestinal transit or by fermentation or ripening during food processing (Kitts & Weiler, 2003). They can have a beneficial effect on a variety of biological systems including the cardiovascular, gastrointestinal, immune and nervous systems (Murray & FitzGerald, 2007).