74 



LIPIDES (fats and RELATED SUBSTANCES) 

 



NaOCCHa + H2SO4 

 Sodium Sulfuric 

 acetate acid 



NaHS04 + HOCCH3 

 Sodium Acetic 



acid sulfate acid 



TRUE FATS 



Definition 



The true fats may be defined as esters of the trihydroxy alcohol, glycerol, 

 and the higher fatty acids. The esters of glycerol are called glycerides, 

 a natural fat being a mixture of various glycerides in different propor- 

 tions. The terms fat and oil are used to distinguish between solid and 

 liquid fats. If the substance is solid at 20°C., it is spoken of as a fat. 

 If it is a liquid at this temperature, it is regarded as an oil. The 

 use of the term oil in this connection must not be confused with its use 

 as applied to so-called mineral oils, such as kerosene oil which is a 

 hydrocarbon, and not related to fats. 



Occurrence and importance 



The fats are abundant in both plant and animal materials such as 

 cottonseed, peanut, coconut, olive, milk, butter, cheese, and meats. The 

 cereals as a rule are comparatively low in fat, since starch takes the 



Table 4r-2 

 Economic importance of some industries based on fats * 



Indiistry 



1. Oils (vegetable and animal) 



2. Butter 



3. Soap and glycerine 



4. Grease and tallow 



5. Shortenings (vegetable) . . . . 



6. Oleomargarine 



Wage 

 earners 

 30,959 

 30,131 1 

 27,660 

 12,472 

 8,003 

 2,567 



111,792 



Value of 

 products 

 shipped 

 $1,741,238,000 

 1,037,000,000 

 1,085,789,000 

 304,535,000 

 884,713,000 

 214,598,000 



$5,267,873,000 



* Compiled from the 1947 Census of Manufactures, Bureau of the Census, 1950, 

 and from the Statistical Abstract of the United States, 1951, published by the Depart- 

 ment of Commerce. 



t Estimated in part. 



place of fat in the composition of such seeds. It is noteworthy that the 

 seeds of the tropical regions of the earth are generally characterized by 



