Possibility of utilizing salmon cannery waste 

 for enzyme production 



Location in Salmon Cannery Waste 



The digestive tract of the fish is a potent source of the comnon 

 hydrolytic or digestive enzymes. In general, peptic, tryptic, amylytic, 

 and lipolytic enzymes are present in fish entrails, the type and amount 

 varying considerably, however, with the species and the specific organ. 

 Norris and Elam (9) isolated from the stomach mucosa of the king salmon 

 a pepsin having unique properties and differing in specificity from 

 mammal pepsins. Johnson (6,7) has done a considerable amount of investi- 

 gating into the enzymatic constituents of fish and he concludes that 

 only the pyloric ceca and the intestinal mucosa offer commercial possi- 

 bilities, with the pyloric ceca yielding about four times as much enzyme 

 as the intestinal mucosa, ^e notes that a dehydrated pyloric ceca powder 

 is approximately seven times as active as the usual commercial leather 

 bate prepared from animal pancreas. Numerous other workers have reported 

 the presence of many specific enzymes in fish; however, the reports are 

 mainly of scientific interest and these enzymes hold little conmercial 

 promise in the present economic picture. 



Percent Composition 



Experimaits have shown that the digestive tract amounts to approxi- 

 mately 6-9 percent of the total salmon waste as it comes from the "Iron 

 Chink" during cannery operations. Thus the pyloric ceca, constituting the 

 major portion of the salmon digestive tract, would approximate 4-6 percent 

 of the total waste. Thus, from 1,000 pounds of waste, 50 pounds of 

 pyloric ceca could be separated yielding about 10 pounds of a dried en- 

 zymatic bate with a potency of 5 to 8 times that of the ordinary ccHmnerclal 

 bates. This concentrate, containing several enzjTnes, primarily exhibits 

 proteolytic activity together with low peptic and lipolytic activity. 

 The amount of purified enzymes th^.t could be extracted fron this concen- 

 trate is unknown at present, but in view of the liigh proteolytic activity, 

 it may be safely assumed that an adequate yield could be recovered. 



Sorting Problems 



One of the primary factors in preparing an enzymatic powder from sal- 

 mon waste is the cost of separating the pyloric ceca. The salmon ceca is 

 a spongelike multi-lobed organ attached to the lower end of the stomach, 

 partially surrounding the duodenum, and attached to each by elastic mem- 

 branes. Ideally, the "Iron Chink" eviscerates the fish cleanly, leaving 

 the digestive organs intact. In practice, however, the machine usually 

 mutilates the organs, tearing off portions of the ceca and the intestines. 

 The segregation of the ceca from the visceral mass would have to be done 

 by hand, and would range from a simple stripping of the intact digestive 

 tract to screening and sorting the voluminous mass of fragments. Ob- 

 viously, the necessity for utilizing extensive hand labor will mean an 

 increased cost of raw material; however, it is believed that with an 

 efficient method of separation, pyloric ceca could be collected at a 



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