CHAPTER 26 



Composition of Fish 



Maurice E. Stansby and H. S. Olcott 



Importance of Composition of Fish 



A knowledge of the chemical composition of fish is of paramount im- 

 portance to evaluate it as regards nutritive value. In industrial processing 

 of fish, a knowledge of composition of fish is important in several ways. 

 Information on oil content of certain species and how the oil content 

 varies with season or with area of capture is needed to evaluate the possi- 

 bility for its utilization in manufacture of oil. Knowledge of proximate 

 composition and especially moisture and oil content are important to 

 determine the yield of such products as fish protein concentrate, fish meal, 

 or other fishery products where drying or oil extraction eliminates mois- 

 ture and oil in the manufacturing process. A knowledge of the kind of oil 

 or protein, i.e., a knowledge of the fatty acid make-up of a fish oil or the 

 amino acid content of a protein, are important for several applications. 

 Thus presence of high proportions of saturated fatty acids in a fish oil 

 will render it less valuable as a drying oil. The pattern of amino acids in 

 a fishery product will be important in determining whether a resulting 

 meal made from it will be suitable as a protein supplement for a stipu- 

 lated use such as for poultry feed. 



Some General Properties of Fish 



Fish are dressed by removal of head, tail, fins, and viscera. Table 26.1 

 gives some information on the proportions of some of the resulting segre- 

 gated parts. Species having a large head such as ling cod give much lower 



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