CLASSES OF FATS 13 



CLASSES OF FATS 



There are two great classes or groups of fats present in the_ 

 butter, namely: 



(1) Volatile and Soluble, 



(2) Non- volatile and Insoluble. 



It was previously stated that little is known concerning the 

 way in which the fatty acids are combined with glycerine in the 

 milk; but, for the sake of convenience, the fats will be referred 

 to as if they existed as separate glycerides of fat. 



The terms " Volatile " and " Non-volatile " are applied to 

 the glycerides of fat, or to the fats as they exist in butter. Strictly 

 speaking, this is not proper, as they do not assume the volatile 

 characteristics until the glycerine separates from the fatty acids; 

 it is only then that the latter become volatile. 



Volatile Fats. The first group, or the volatile fats, include 

 butyrin, caproin, caprylin, caprin, and laurin. Butyrin is the 

 one present in the largest proportion. Laurin and caprin are 

 partially non-volatile. Butyrin is the most important fat 

 belonging to the volatile group. It is the most important quan- 

 titatively and also qualitatively. So far as is known, butyrin 

 is the least stable of any of the butter-fats. Under normal con- 

 ditions, so long as the fatty acid remains in combination with the 

 glycerol, it is neither volatile nor soluble in water; but as soon 

 as separation takes place, due to the action of micro-organisms, 

 or to the effect of light and air, it becomes volatile, and escapes 

 in the form of gas. 



It is also claimed that these volatile fats have the special 

 properties of absorbing odors and gases to a greater extent than 

 any of the other fats. This absorption takes place when fat 

 comes into contact with the undesirable taints. For this reason 

 it is essential that milk, cream or butter be kept away from any 

 foreign, undesirable odors. These taints may also be imparted 

 to the fat before the milk is drawn. If the cow is fed on unde- 

 sirable food, such as turnips, onions, garlic, etc., the milk from the 

 cow assumes undesirable characteristic flavors which can easily be 

 recognized in the finished product. On the other hand, such 



