The Composition and Structure of Milk Lipids

Abstract

The lipids of milk provide energy and many essential nutrients for the newborn animal. They also have distinctive physical properties that affect the processing of dairy products. In this review, the compositions and structures of both the major and minor components in milk lipids of many species are compared, and the data are discussed in terms of the nutrient requirements of the neonatal animal. The content and composition of milks from different species vary widely; presumably, these are evolutionary adaptations to differing environments. On the other hand, the distributions of lipid classes in milks are very similar. The fatty acid compositions of milks are usually complex and distinctive, depending on the nature of the fatty acids synthesized de novo in the mammary gland and those received from the diet in each species. Characteristically, they contain short- and medium- chain fatty acids not found in other tissues. Triacylglycerols, the main lipid class, of milks from different species do, however, exhibit many structural similarities.