Milk is a highest quality source of well-balanced nutrients and also displays a range of biological activities that affects digestion, metabolic responses to absorbed nutrients, growth and development of specific organs, and resistance to disease. Bioactive peptides have been identified within the amino acid sequences of native milk proteins. Hydrolytic reactions, such as those catalyzed by digestive enzymes, result in their release. These peptides directly influence numerous biological processes evoking behavioral, gastrointestinal, hormonal, immunological, neurological, and nutritional responses.. The size of active sequences may vary from two to twenty amino acid residues. The total antimicrobial effect in milk is greater than the sum of the individual contributions of immunoglobulin and nonimmunoglobulin defense proteins such as lactoferrin, lactoferricin , and other peptides. A variety of naturally formed bioactive peptides have been found in fermented dairy products, such as yoghurt, sour milk and cheese. Bioactive peptides have the potential to be used in the formulation of health-enhancing nutraceuticals, and as potent drugs with well defined pharmacological effects
