USES OF INDUSTRIAL FISH OILS 



Table 21.1. U.S. Supply of Fish Oils,* 1950-1960 

 (Excluding liver, whale, and sperm oil) 



261 



* Conversion factor: 7.5 pounds per gallon. 



t Includes small amounts of nonmedicinal liver oils. 



t Preliminary estimate from incomplete figures. 



investigated from the standpoint of fatty acid composition of the com- 

 mercial crude oils^^ The relative amounts of saturated and unsaturated 

 fatty acids coincides with the known physical properties of the crude oil. 

 Table 21.3 summarizes the principal fatty acids from crude menhaden oils 

 produced in the United States during the 1960-1961 season. 



Chemical Modifications of Fish Oils 



The industrial utilization of products derived from fish oils depends on 

 the kinds of chemical modifications of the oils as well as the chemical and 

 physical properties of the products. Fish oils can be chemically altered by 

 reactions of the ethylenic bonds or so-called ''double bonds" in the un- 

 saturated fatty acid portion of the oils or by reactions of the carboxyl 

 groups of the fatty acids from the oils (see Ref. 19). Chemical reactivity 

 of fish oils and their fatty acid derivatives depend on the number and 

 class of functional groups found on each molecule. Like chemical reac- 

 tivity, the physical properties of fish oil products depend on the nature 

 of chemical functional groups. Viscosity, solubility, acidity, melting 

 point, and physical state are typical properties influenced by the nature 

 of chemical functional groups. 



Chemical modifications of the ethylenic bonds in fish oils are considered 

 to be the most important from the standpoint of economic success because 

 they make use of the uniqueness of these oils as compared to other natural 

 fats and oils. A common chemical reaction of this type is that of hydro- 

 genation. Hydrogen can react with the ethylenic bonds to cause hardening 



