Handbook of Food Science and Technology 3

Figure 1.1.
 Composition and main characteristics of milk fat globules 

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From Milk to Dairy Products 5 
1.1.1.1.
 Composition and characteristics of milk fat 
Table 1.1 shows the average lipid composition of cow’s milk. 
Triacylglycerols represent approximately 97.5% of the total lipids. 
Diacylglycerols, monoacylglycerols and free fatty acids are naturally present 
in small amounts but their proportion can increase with lipolysis. The many 
other compounds (cholesterol, steroid hormones, vitamins, flavorings and 
flavor substrates, etc.), even though low in number, play a crucial nutritional 
and sensory role. 
Class of lipids 
Percentage of total lipids (w/w) 
Triacylglycerols 
97.5 
Diacylglycerols 
0.36 
Monoacylglycerols 
0.027 
Free fatty acids 
0.1 
Cholesterol 
0.31 
Hydrocarbons 
Traces 
Carotenoids 
0.008 
Phospholipids 
0.6 
Table 1.1. 
Average lipid composition
of cow’s milk (Source: [CHR 95]) 
Milk triacylglycerols are made up of more than 400 different fatty acids, 
which makes milk fat a very complex lipid source, as each fatty acid can be 
esterified to one of the three hydroxyl groups of glycerol (Table 1.2). 
However, only 12 fatty acids are present in quantities of more than 1% 
(mol/mol). Fatty acids are either synthesized in the secretory cells in the udder 
or taken from the bloodstream (body fat or food origin). Thus, milk fat varies 
depending on the season, the cow’s diet and the energy level of the food 
intake, which could determine the ratio of 
de novo
synthesis with regard to 
plasma uptake. 

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6 Handbook of Food Science and Technology 3 
Fatty acids Symbol % mol 
Distribution on the glycerol sites (% mol)
Melting point (°C) 
Sn1 Sn2 Sn3 
Butyric 
4:0 
4.8 
- 
- 
35.4 
-7.9 
Caproic 
6:0 
2.2 
- 
0.9 
12.9 
-1.5 
Caprylic 
8:0 
1.3 
1.4 
0.7 
3.6 
+16.5 
Capric 
10:0 
2.9 
1.9 
3.0 
6.2 
+31.4 
Lauric 
12:0 
3.3 
4.9 
6.2 
0.6 
+43.6 
Myristic 
14:0 
10.8 
9.7 
17.5 
6.4 
+53.8 
Palmitic 
16:0 
26.1 
34.0 
32.3 
5.4 
+62.6 
Palmitoleic 16:1 
1.4 
2.8 
3.6 
1.4 
-0.5 
Stearic 
18:0 
10.8 
10.3 
9.5 
1.2 
+69.3 
Oleic 
18:1 
24.1 
30.0 
18.9 
23.1 
+14.0 
Linoleic 
18:2 
2.4 
1.7 
2.5 
2.3 
-5.0 
Linolenic 
18:3 
1.1 
- 
- 
- 
-11.0