ABSTRACT
Milk fat has the most complex structure and chemical composition of all food lipids. This chapter deals with lipids found in bovine milk, although the milk of other mammals follows the same general principles. Lipids in milk are typically found at a concentration of 3.5-5.0 g/100 g milk, in the form of emulsiŒed globules dispersed in the aqueous phase. The globules range in diameter from 0.1 to 10 μm and are basically a core of triacylglycerols (TAG) surrounded by a thin (8-10 nm) bilayer milk fat globule membrane (MFGM) that maintains the integrity of the globule. The TAGs are nonpolar molecules consisting of three fatty acid (FA) molecules esteriŒed onto a backbone of glycerol. The TAG core of the globule also contains small amounts of cholesteryl and retinol esters. The MFGM consists of proteins and lipids, with the latter mainly being phospholipids, cholesterol, and glycolipids. There are approximately 1.5 × 1010 fat globules in 1 mL of milk, with a surface area of about 2 m2.
