Structure of milk lipids

Esterification of fatty acids is not random Cij-Cig are esterified principally at the sn-2 position while and Cg are esterified principally at the sm-3 position (Table 3.8). The concentrations of C4 and Cjg appear to be rate-limiting because of the need to keep the lipid liquid at body temperature. Some features of the structures are notable  

Fatty acid distribution is significant from two viewpoints  

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Christie, W. M. W. 1983. The composition and structure of milk lipids. In Developments in Dairy Chemistry, Vol. 2., Lipids. P. F. Fox (Editor). Applied Science Publishers, New York, pp. 1-35. 

Christie, W.W. 1994. Composition and structure of milk lipids. In Advanced Dairy Chemistry Vol. 2, Lipids, 2nd edn. (P.F. Fox, ed.), Chapman and Hall, London, pp. 1-36. Christensen, T.C., Holmer, G. 1993. Lipase catalyzed acyl-exchange reactions of butteroil, synthesis of a human milk fat substitute for infant formulas. Milchwissenschaft 48, 543-548. 

W. W. Christie, Advanced Dairy Chemistry Lipids, Vol 2, 2nd edition Composition and Structure of Milk Lipids, (ed. P.F. Fox) Chapman Hall, London (1994), pp.1-36. P. Walstra, Advanced Dairy Chemistry Lipids, Vol. 2, 2nd edition Physical Chemistry of Milk Fat Globules (ed. P.F. Fox) Chapman Hall, London (1994), pp. 131-178. R.G. Jensen, The Lipids in Human Milk, Progress in Lipid Research, 1996, 35, 53-92. R.G. Jensen (ed.) Handbook of Milk Composition, Academic Press, San Diego, California (1995). 

German, J. B., and Dillard, C. J. (2006). Composition, structure and absorption of milk lipids A source of energy, fat-soluble nutrients and bioactive molecules. Crit. Rev. Food Sci. Nutr. 46, 57-92. 

Timmen, H. and Dimick, P. S. 1972. Structure and synthesis of milk fat. X. Characterization of the major hydroxy compounds of milk lipids. J. Dairy Sci. 55, 919-925. 

The structure of milk triglycerides is considered in Chapter 4. Here we emphasize only that many different triglyceride molecules are present in lipid globules. Whether these triglycerides are randomly distributed throughout the core or are concentrated into discrete zones or... 

To date, little attention has been given to the native structural properties of milk lipids. In particular, little is known about how these structural... 

Keenan, T., Patton, S. 1995. The structure of milk implications for sampling and storage A. The milk lipid globular membrane. In Handbook of Milk Composition (R.G. Jensen, ed.), pp. 5 44, Academic Press, Inc., San Diego. 

Keenan, T.W. and Dylewski, D.P. (1995) Intracellular origin of milk lipid globules and the nature and structure of the milk lipid globule membrane, in Advanced Dairy Chemistry, Vol. 2 Lipids, 2nd edn, (ed. P.F. Fox), Chapman Hall, London, pp. 89-130. 

Table 10.4. Structures of Glycosphingollplds of Bovine Milk Lipid Globule Membrane.

Franke, W. W. and Keenan, T. W. 1979. Interaction of secretory vesicle membrane coat structures with membrane free areas of forming milk lipid globules. J. Dairy Sci. 62, 1322-1325. 

Full fat milk contains about 3% fat and triacylglycerols account for about 95% of the lipid fraction. Other components of the lipid fraction are diacylglycerols, cholesterol, phospholipids, and free fatty acids. The lipid structures contain many fatty acids from all major classes, that is, saturated, monounsaturated, and polyunsaturated fatty acids (Haug et al., 2007). More than 60% of the fatty acids in cow s milk and consequently in dairy products are saturated, including shorter and medium... 

The use of surfactants in the food industry has been known for centuries. Naturally occurring surfactants such as lecithin from egg yolk or soybean and various proteins from milk are used for the preparation of many food products, such as mayonnaise, salad creams, dressing, and desserts. Polar lipids such as monoglycerides have been introduced as emulsifiers for food products. More recently, synthetic surfactants such as sorbitan esters (Spans) and their ethoxylates (Tweens), sucrose esters, have been used in food emulsions. It should be mentioned that the structures of many food emulsions is complex, and in... 

These studies demonstrate that treatments that have been reported to modify the heat stability of milk also may change the distribution of tracer milk proteins between the physical phases of milk. Analysis of these interactions may provide useful information about the mechanisms of these effects. In unpublished experiments, we have extended this approach for studying homogenized milk-based systems, also containing a lipid phase, to investigate lipid-protein interactions. Dual-label experiments, for example in milk containing M-/3-L and 3H-methyl-/c-casein, could be applied to the isolation and characterization of protein complexes in milk. Labeled caseins could prove valuable as probes for elucidating micelle structure. 

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