The proteins of milk are of great importance in human nutrition and influence the behavior and properties of the dairy products containing them.
Milk contains a wide range of protein that provide protection against enteropathogens or are essential for the manufacture and characteristic nature do certain dairy products.
Milk proteins, because of high surface activity, rapidly adsorb at the oil-water interface, producing the surface layer that stabilize oil/fat droplets against flocculation or coalescence.
Milk contains a number of different proteins and can be classified to:
1. Casein
2. Whey proteins
3. Milk fat globule membrane
4. Minor proteins
5. Enzymes
Casein and whey are the two predominant types of protein found in milk.
Casein is a phosphoprotein, meaning that phosphate groups are attached to some of the amino acid side chains. Casein exists in milk as the calcium caseinate. This salt has a complex structure.
Whey is the liquid portion of milk, consisting primarily of 93% water, lactose, whey proteins (primarily lactalbumin and lactoglobulin).
Both casein and whey protein have been found to be increasingly important for physiological and biochemical functions that have crucial impacts on human metabolism and health.
Biological active peptides released from caseins and whey proteins contain 3 to 20 amino acids per molecule.
Researchers have demonstrated that these peptides posses very important biological functionalities, including antimicrobial, antihypertensive, anti oxidative, anticytotoxic, immunemodularity, opioid and mineral carrying activities.
Protein in milk
