Further tests, especially those employing a salmon canning oil 

 prepared by pressure cooking the heads, should be carried out. These 

 tests would offer additional evidence on the question of imparting 

 flavor to the canned salmon. On the basis of the organoleptic tests 

 herein reported, there is not sufficient conclusive evidence ttet the 

 reported preference for the unoiled salmon is due entirely to flavors 

 attributable to the added oil. From the standpoint of accelerated 

 undesirable changes in storage over a period of eight months, there 

 is some slight evidence that the samples containing added oils may be 

 more susceptible. This trend vd.ll have to be followed for a longer 

 storage period before definite evidence can be obtained on this point. 



PROCESSING SALMON CAJJNERY WASTE FOR RECOVERY OF VITAMIN A OILS 

 By Clarence J.Carlson and Harris W.M^gnusson 1/ 



Introduction 



During the summer of 1947 an investigation of the alkali diges- 

 tion of salmon cannery waste on a pilot plant scale was started. This 

 work was conducted in a cannery in Seldovia, Alaska. The results of 

 this research were reported ty Butler aild Miyauchi (l). The proced- 

 ure used was a modification of the method recanmended by Anderson (2) 

 on the basis of studies of very small lots of salmon head and collar 

 sections. The investigation at Seldovia studied the application of 

 this method to various portions of salmon cannery waste. Waste from 

 each of the five species of salmon were digested experimentally, and 

 numerous studies were made to test the effectiveness of processing only 

 certain parts. Especially considered were the parts in which the oil 

 or the vitamin A were most concentrated, such as head, liver and vis- 

 cera. Tests were also performed using whole waste less the eggs and 

 milt, which two parts are most likely to cause emulsions. 



At the Fishery Products Laboratory in Ketchikan, beginning in the 

 summer of 1947 and continuing through the following winter, a study 

 was made to determine the most effective procedure for recovery of maxi- 

 mum amounts of oil and vitamin A f]x>m whole waste. In this study none 

 of the parts were removed. The particle size of the raw material, the 

 concentration of alkali used, and the time and temperature of the diges- 

 tion were varied. For each variation of the digestion procedure the 

 yields of oil and vitamin A were determined. 



Collection of Raw ^terials 



The raw materials used in this series of experiments consisted of 

 the whole waste of only one species of fish, the pink salmon C Oncorhyn- 

 chus gorbuscha ) . All of the waste was collected from the cannery of 

 the Ketchikan Packing Company, which handles only trap-cau^t salmon. 



1/ Chemists, Fishery Products Laboratory, Ketchikan. Alaska, Alaska 

 eries Experimental Conmission and Fish and Wildlife Service. 



Fish- 

 l 'Fish and Wiidlife Service. 



98 



