Definition and Nutritional Values of Milk
Milk is the normal secretion of the mammary glands for the feeding of the young of mammals. In the United States, the primary milk in this food products rest primarily with the individual states rather than with the federal government. Consequently, legal definitions of milk are not uniform within the United States. The U.S Public Health Service has encouraged the adoption of adequate and uniform state and local control registration. The following definition from its Grade A Pasteurized Milk Ordinance (1965) has been adopted by a majority of the states.
“Milk is hereby defined to be the lacteal secretion, practically free from colostrum, obtained by the complete milking of one or more healthy cows, which contains not less than 8.25% milk solids not fat and not less than 3.25% milk fat.”
The composition of milk is rather complex. Of the major components of milk, the one that most readily distinguishes milk from other foods is lactose, which occurs naturally only in milk. Similarly, casein occurs in milk. The proteins of milk are great importance and contribute essential amino acids necessary for normal health and growth. Milk fat is a palatable mixture of glycerides of fatty acids. The components are in the complex equilibrium, and much is yet to be learned regarding the forms and combinations in which they exist. Lactose and some mineral salts are in the true solutions; the milk proteins as well as some of the calcium phosphate exist in colloidal solution; the fat exists in macroscopic dispersion in the milk plasma. Besides these major constituent, milk contains other constituents such as vitamin, enzymes, pigments and lactic acid.Definition and Nutritional Values of Milk
