tion of Alaskan salmon canneiy waste directed attention to an investi- 

 gation of the possible use of salmon eggs for the production of choles- 

 terol, protein, and industrial fat. It was necessary to limit the pro- 

 posed investigation to a period of not longer than six months, or the 

 duration of the Industrial Research and Development Division contract 

 with the Alaska Fisheries Experimental Commission. The study was planned 

 so that the necessary factual information required to evaluate the possi- 

 bilities of further development could be collected in the time allotted 

 for experimental study. From analytical data reported in the literature, 

 the use of salmon eggs as a source of cholesterol appeared promising. It 

 was thought that commercial development mi^t be practical if experimeJa- 

 tal tests showed the cholesterol content of the salmon eggs studied to be 

 as high a;, had been previously reported. It was believed very likely 

 that in addition to cholesterol extraction, processes could be develop- 

 ed which would also permit recovery of a high quality protein meal from 

 salmon eggs as well as a fat or lipide 1/ fraction which would have a 

 number of important industrial applications. 



Cholesterol, a monatoraic alcohol and a member of the group of cotk 

 pounds known as sterols, has the empirical formula C2'7Hi rOH. It is a 

 primary cell constituent and is present in fairly large amounts in nerve 

 tissue. As pointed out in the prelir.iinary report by Jones and Carrigan (?)> 

 several investigators have reported on the presence of cholesterol in 

 fish roe. Koenig and Grossfeld (8) reported that the fat fixjm fish roe 

 contains from 4 to 14 percent cholesterol. Anno (l) found that the un- 

 saponifiable matter present in the lipides of salmon eggs was essential- 

 ly cholesteixjl. 



Cholesterol has been in much demand for the manufacture of synthetic 

 vitamin D and for use in the preparation of various pharmaceutical and 

 cosmetic articles. Pure cholesterol for subsequent manufacture of syn- 

 thetic vitamin D commands an average market price of $12.00 a pound. Con- 

 siderable quantity of pure cholesterol is prepared from the spinal cords 

 of meat animals. Improved methods of cholesterol production from wool 

 grease recently announced in the technical literature (2,10) may cause 

 a drop in the present favorable market price. There is also a consider- 

 able demand for lecithin, which is an important constituent of the lip- 

 ide fraction of salmon eggs. However, lecithin at present is being pro- 

 duced conmercially on such a large scale from soy beans cind other vege- 

 table sources, that it is extremely doubtful if its production from 

 salmon egg fat would be economically possible iinless it was obtained 

 incidental to the recovery of other substances. If salmon eggs were 

 being processed for cholesterol and protein, it is possible that econom- 

 ic recovery of lecithin could be developed. Koenig and Grossfeld (8) 

 in considering fish roe as food for man fo\ind the egg fat to contain as 

 much as 49 percent lecithin. Halpem (5) reported in 1945 that the roe 

 from sockeye salmon yielded 12.5 percent oil and 6.2 percent phospholip- 

 ide. The phospholipides of salmon eg£e are composed principally of 



1/ The term "lipide" used in this report includes both neutral fats and 

 the phospholipides. 



66 



