CHAPTER III 

 MILK FATS 



29. Composition of Fats. — The fat srlobules of 

 milk are a mechanical mixture of several separate 

 fats. All fats are composed of the elements carbon, 

 hydrogen, and oxygen ; but individual fats differ in 

 the way in which these elements are combined. In 

 all the fats, carbon, the principal element found in 

 coal, is present to the extent of over 75 per cent. The 

 fats as a class do not contain any nitrogen, differing 

 in this respect from casein and albumin, which con- 

 tain about 16 percent of this element. Each fat has 

 its own melting point, form of crystals, specific 

 gravity, and other characteristics, and hence the 

 physical properties of butter are largely dependent 

 upon the proportion in which the principal fats are 

 present. Some of the milk fats are hard, and have a 

 high melting point, while others are liquid. The 

 character of butter, as hard or soft, is dependent 

 largely upon the proportion in which the various 

 fats, as stearin, palmitin, and olein, are present. 



30. Kinds of Butter Fats. — The various fats which 

 are present in butter are butyrin, caproin, caprylin, 

 laurin, palmitin, myristin, stearin, and olein. Of 



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