NUTRITIVE VALUE OF FISH AND SHELLFISH 535 



mackerel, 86 per cent for butterfish, 94 per cent for dogfish, and 94 

 per cent for salmon. 



From this limited data concerning the digestibility of fish fats one 

 is inclined to conclude that they are quite satisfactorily utilized by 

 the human body. 



PALATABILITY < 



The ])alatability of fish oils is influenced by many factors. When 

 the oils are separated from the fish and prepared for consumption, 

 careful attention should be given to the source of the oil and manu- 

 facturing conditions. It is essential that the body or liver of fish 

 from which the oils are extracted should be strictly fresh. Manu- 

 facturing processes, also, should be developed so that only the highest 

 possible grade product is produced. 



At the present time the greater portion of fish oils is consumed in 

 conjmiction with the tissues in which they naturally occur. Many 

 people are very fond of fat-rich fish, such as butterfish, mackerel, 

 and salmon, and as a result add fish oils to their dietary. Persons 

 who desire to increase the fat content of their diet do not consider 

 eating lard for that purpose. However, they often find crisp bacon 

 very appetizing. In the same manner one may not wish to include 

 separated fish oils in the dietary but would find well-cooked, fat-rich 

 fish a welcome addition to their daily fare. In fact, those who are 

 accustomed to eating fish often become very enthusiastic concerning 

 the unusual palatability of broiled mackerel or broiled fresh salmon 

 when done to a turn and well garnished with a little parsley and plenty 

 of fresh lemon juice. 



PRESENT CONSUMPTION 



It is difficult to accurately estimate the quantity of fish fats used 

 for food. Relatively speaking, very little fish fat is included in the 

 human dietaiy as such, but large amounts are eaten in conjunction 

 with the flesh of some of the well-known fat fish. For instance, the 

 1923 pack of salmon amounted to 6,500,000 cases, or 312,000,000 

 pouncis. Since canned sahnon contains nearly 11 per cent of oil, 

 this amount contributed something like 33,900,000 pounds of sahnon 

 body oil to the human dietary. 



The amount of oil which may be contributed by other fish can be 

 estimated if one remembers that 16,000,000 pounds of mackerel have 

 been taken by the New Eii^land fisheries in one season; that a single 

 year's catch of butterfish off the New York- New Jersey coast amount- 

 ed to 5,000,000 pounds; and that the edible portions of these fish at 

 some seasons may contain as much as 12 per cent fat. Perhaps a 

 better conception of the amount of fish oil which finds its Vv'ay into 

 the human dietary can be gained if it is noted that of the many 

 millions of pounds of fish caught the general average percentage of 

 fat is about 10 per cent of the edible portion. 



A consideration of fish and marine animal oils would not be com- 

 plete without mention of whale oil. Many romances of the sea have 

 centered about expeditions of whaling vessels. In earlier times 

 whale oil was used largely for illumination, but with the advent of 

 kerosene, gas, and. electricity relatively little whale oil is now used 

 for that purpose. 



