Antibacterial Peptides from Goat and Sheep Milk Proteins

Milk is an excellent source of well balanced nutrients and also exhibits a range of biological activities that influence digestion, metabolic responses to absorbed nutrients, growth and development of specific organs, and resistance to disease. Goat milk is as close to perfect food as possible in nature. Bioactive peptides have been defined as specific protein fragments that have a positive impact on body functions or conditions and may ultimately influence health. It can be generated during milk fermentation by the proteolytic activity of starter cultures. The beneficial health effects may be classified as antimicrobial, antioxidative, antithrombotic, antihypertensive and immunomodulatory. Sheep and goat milk proteins are also important sources of bioactive ACE inhibitory peptides and antihypertensive peptides. They can provide a non- immune disease defence and control of microbial infections. The activity of these biofunctional peptides is based on their inherent amino acid composition and sequence. The size of active sequences may vary from two to twenty amino acid residues. The total antibacterial effect in milk is greater than the sum of the individual contributions of immunoglobulin and nonimmunoglobulin defence proteins such as LF, LP, lysozyme, and other peptides. A variety of naturally formed bioactive peptides have been found in fermented dairy products, such as yoghurt, sour milk and cheese. BP have the potential to be used in the formulation of health-enhancing nutraceuticals, and as potent drugs with well defined pharmacological effects.