Triglycerides which make up 95 - 98% of milk fat and are of particular interest to those involved in food production, processing and preparation. They are the primary component of butterfat. The actual amount of butter fat in milk varies depending upon the individual cow. Whole milk contains 3.6 to 4.2% lipids, depending upon the cow, season, feed, and a number of other subtle factors. For those of us growing upon a farm, it was well understood that Holsteins would give lots of milk that was relatively low in fat. Gurnseys and Jerseys gave rich, high butterfat milk.
Certainly, fat is removed from milk and sold as "butter". Another high fat product is whipping cream which has 30-36% butterfat. Whipping cream use to have approximately 36%. However, technological innovation and the addition of stabilizers decreased butterfat content.
| Lipid Classes | Approximate
Percentage |
| Triglycerides | 95.00-98.00 |
| Diglycerides | 0.25-3.50 |
| Monoglycerides | 0.01-0.04 |
| Ketoglycerides | 0.80-1.20 |
Hydroxyacid
Glycerides | 0.05 |
| Sterol | 0.30 |
| sterol Esters | 0.02 |
| Free Fatty Acids | 0.1-0.4 |
| Methyl Ketones | trace |
| Phospholipids | 0.20-1.00 |
| Lactones | trace |
| Cerebrosides | 0.04 |
| Non-saponifiable | 0.20-0.50 |
|
Milk is generally emulsified as shown below. Note that it binds up some of the protein to bring about emulsification. This in itself has potential for further problems.
|
|
 |
