548 



U. S. BUREAU OF FISHERIES 



The composition of the flesh of the five species of salmon differs 

 somewhat. The following table from Bureau of Fisheries Document 

 No. 1000 entitled "Nutritive value of fish and shellfish," Washington, 

 D. C. (1926), gives the average of many analyses, together with 

 analyses of steelhead trout and Atlantic sajmon for comparison: 



Composition oj canned salmon 



Note. — For certain reasons the backbone and as much as possible of the rib bone were removed from 

 these cans before analyzing, hut ordinarily they are eaten and thus increase the valuable mineral con- 

 stituents in the food. 



ANALYSES OF CANNED SALMON BY SOUTH DAKOTA AUTHORITIES 



In 1916 the South Dakota Food and Drug Department analyzed a 

 considerable number of samples of canned salmon for the purpose of 

 determining, if possible, whether inferior grades of the fish were sub- 

 stituted for the better grades, and for the further purpose of discov- 

 ering some means of identifying the different types of salmon by 

 chemical analysis. 



Thirty-three samples of commei'cial canned salmon, including 30 different 

 brands, were analyzed. Thirteen of these were labeled as belonging to the 

 sockeye class, five to the coho, six to the humpback, and one to the chum. Five 

 samples were not labeled as to variety. One sample was labeled "Salmon 

 Steaks" and two samples were labeled "Fresh Alaska." The last eight samples, 

 because they were not labeled to show the common name of the fish contained 

 in the can, were in violation of the F. I. D. No. 105 referred to above. 



All of the cans but one were labeled to show the net weight of fish in the can. 

 Sixteen per cent of them contained less than the declared amount of contents, 

 but the greatest shortage was but 3.1 per cent of the declared weight, while the 

 greatest excess in weight was 18.7 per cent of the declared weight. The weight 

 is usually stated considerably under the actual amount of the contents. 



The amount of liquid in the cans is an important factor to consider in com- 

 puting the value of the contents. The free liciuor in the cans examined varied 

 widely from 3.95 per cent in sample number 15-209, labeled "Salmon Steaks " to 

 26.54 per cent in sample number 15-63, which was not labeled as to variety. 

 As a rule, the largest amount of free liquor is found in the lower priced grades, 

 but there are exceptions, notably number 15-70, which contained 24.14 per cent 

 of free liquor. 



It will be noticed from the results given in the table that the amount of total 

 moisture varies inversely as tlie amount of fat (called ether extract in the table). 

 That is, salmon containing an excessive amount of moisture contains little fat, 

 Vjut those samples which contain the lower amounts of moisture contain the 

 largest amounts of fat. The protein content seems to be fairly constant in all 

 samples, the average amount being 19.34 per cent, while the minimum found is 

 15.66 per cent and the maximum 22.45 per cent. The total phosphoric acid 

 varies from 4.2 per cent to 9.8 per cent, the average being 6.6 per cent. 



As would be expected, the samples containing the larger proportions of fat 

 liberate the larger quantities of heat units, or calorics, per pound, and it will be 

 noted that the price is not in all cases an accurate measure of value, some of 

 the higher priced varieties being in reality much lower in actual cost, when their 

 food value is taken into consideration, than some of the cheaper varieties.^^ 



M Bulletin, South Dakota Food and Drug Department, Vol. IV, Nos. 2 and 3, October-December, 1916, 

 pp. 8-11. 



