Bioactive peptides: new challenges and opportunities for the dairy industry

Milk proteins are known to exert a wide range of nutritional, functional and biological activities that make them potential ingredients of health-promoting foods. These properties are partially attributed to physiologically active peptides encrypted in the protein molecules. Such peptides are inactive within the sequence of the parent protein molecule and can be liberated during gastrointestinal digestion or milk fermentation by proteolytic enzymes. Milk protein-derived bioactive peptides may exert a number of physiological effects in vivo, e.g. on the gastrointestinal, cardiovascular, endocrine, immune and nervous systems. For the time being, industrial-scale manufacture of such peptides is limited by the lack of suitable technologies. Bioactive peptides have been identified in various traditional fermented dairy products but the potential health-affecting role of these peptides is not known. On the other hand, dairy products enriched with milk protein-derived bioactive peptides have been commercialised and this trend is likely to continue. There is a need to develop technologies that optimise the activity of bioactive peptides in food systems and enable optimum utilisation of such peptides in the body. This review highlights the current technologies applicable for production of bioactive peptides, their occurrence in dairy foods and potential for health promotion.