Milk Proteins: General and Historical Aspects

Abstract

Milk is a fluid secreted by the female of all mammalian species, of which there are about 4,500, primarily to meet the complete nutritional requirements of the neonate. The principal requirements are for energy (supplied by lipids and lactose and, when in excess, by proteins), essential amino acids and amino groups for the biosynthyesis of non-essential amino acids (both supplied by proteins), essential fatty acids, vitamins and inorganic elements and, of course, water. Because the nutritional requirements of the neonate depend on its maturity at birth, its growth rate and its energy requirements, which depend mainly on environmental temperature, the gross composition of milk shows large inter-species differences which reflect these requirements. The gross composition of the milk of a number of species is shown in Table 1.1. How well the milk protein system meets the nutritional requirements for protein is discussed in Chapter 12.