shaken for 30 seconds, swirled to facilitate separation, and then 

 allowed to stand for 15 minutes. With saLnion eggs a more satisfac- 

 tory separation was obtained by using only ethyl ether, instead of 

 the 25-25 mixture of ethyl ether and petroleum ether usually recom- 

 mended. The ether layer was poured into a 250-millil-;ter separatory 

 funnel. Two subsequent 35-niilliliter washes with ethyl ether were 

 made sind added to the first extracticai. Fifty milliliters of water 

 were added to the ccnbined ether extractions and the wiiole shaken 

 and allowed to separate for 10 minutes. The water layer was drawn 

 off and discaivled. Tlie ether layer was filtered through a medium 

 porosity sintered glass filter provided with a l/4-inch layer of an- 

 hydrous sodium sulfate. The filtrate was collected in a 150-milli- 

 liter tared beaker, and the ether evaporated in a current of warm air. 

 Th« •Ktitictive was then placed in an air oven at 105°C. for one hour, 

 cooled in air for 30 minutes, and weired. 



Unsaponifiable Matter 



Tha unsaponifiable fraction of the fat was determined in duplicate 

 on the ether extract from the above described fat determination using 

 the official method of the A.O.A.C. for unsaponifiable residue in oils, 

 fats and waxes. The final unsaponifiable residue as isolated by this 

 procedure was dried to constant weight at 105°C. and allowed to cool 

 in air for 30 minutes before weighing. 



Results and Discussion 



Although published reports indicated that the cholesterol content 

 of salmon egg fat varies from 4 to lA percent, the carefully controlled 

 experiments reported here failed to disclose any values hi^er than 

 3. -53 percent. As Indicated in Table 1, the cholesterol ccsitent of the 

 egg Scimples of the five species of salmon examined did not exceed 3.53 

 percent on the liplde fraction or 0.40 percait on the raw egg basis. 



TABLE 1 . — Average Composition of Sa-lmoa Eggs 



Species of Cholesterol 



Salmon Moisture Fat 1/ In Raw Eggs In Fat 



Percent Percent Percent Percent 



Pink 59.5 11.1 0.29 2.61 



Red 54.7 13.9 0.39 2.82 



Chum 55.4 11.9 0.38 3.15 



" (dehydrated)^ 0.5 28.0 0.86 3-06 



King 62.2 12.8 0.34 2.64 



Coho 60.3 11.4 0.40 3.53 



1/ Total ether extract after acid hydrolysis of sample. 

 2/ This is a dehydrated sample prepared by lyophilization. 



71 



