US EPA

5232077 

Journal Article 

Composition of milk fat Introduction 

Sebedio, JL 

2008 

1 

Sciences des Aliments
ISSN: 0240-8813 

28 

1-2 

5-11 

10.3166/sda.28.5-11 

WOS:000264717300001 

Ruminant milk contains from 3 to 5% fat. Milk fat is a complex mixture of triacylglycerols, di-and mono-acylglycerols, complex lipids and of fat soluble components. Milk fat is present as globules which are covered by a membrane. The membrane is mainly composed of phospholipids, glycolipids and enzymes while the core of the milk fat globules is mainly composed of triacylglycerols. In fact triacyglycerols represent more than 95% of the total lipids. Saturated fatty acids represent from 65-70% of total fatty acids. The major ones are myristic acid or 14:0 (10-12%), palmitic acid (25-35%), and stearic acid (10%). Other saturated fatty acids include short (C4, C6) and middle chain (C8-C14) isomers as well as branched and odd carbon number fatty acids. Oleic acid is one of the major fatty acids, representing around 20-25% of the total fatty acids of milk fat. Milk fat also includes trans fatty acids, the major isomer being vaccenic acid or 18:1-11t and conjugated fatty acids, rumenic acid or 18:2-9c, 11t representing more than 90% of the total conjugated fatty acid isomers. Fatty acid composition of milk fat can be modulated by different factors which include the type of feeding, the season, the number of lactation and the animal breed. Polar lipids which are minor components of milk fat are mainly constituted of glycerophospholipids and sphingolipids. Milk fat also contains 4 fat soluble vitamins (A, D, E, and K) as well as carotenoids. 

milk; ruminant; fatty acids; fat soluble vitamins; phospholipids; composition