which have not been successfully synthesized on a commercial settle, so 

 that where their use is indicated obviously the natural form is the only 

 one available. Chemical synthesis has been successful in producing ade- 

 quate quantities of the amino acids: methionine, isoleucine, valine, 

 threonine, phenylalanine, tryptophane, and lysine. The resulting synthetic 

 acids are equal mixtures of the natural (biologically active) and unnatural 

 (biologically inactive) forms. Although it is theoretically possible to 

 resolve these two forms by chemical methods, the procedures are laborious 

 and impractical for quantity production. 



Many different kinds of materials are used in the preparation of the 

 natural-occurring amino acids. At the present time a number of competing 

 raw materials are being exploited. For example, sodium glutamate, which 

 has been mentioned before in this report is being successfully prepared 

 from a gluten byproduct in tlie milling of wheat, and also from "Steffens 

 waste", a byproduct occurring during the refining of beet sugar. Soy- 

 bean hydro lysates have also been used. A number of important amino acids 

 have been produced in sizeable quantities from fish residues of the tuna 

 and mackerel canning operations. 



The present market for amino acids is somewhat limited due to their 

 comparatively high cost. When this cost is reduced, it is believed that 

 certain of the amino acids will gain wider usage in medicine and in human 

 and animal nutrition. 



Possibility of utilizing salmon cannery waste 

 for production of amino acids 



Location in Salmon Cannery Waste 



The proteins of salmon waste suggested as being suitable for the 

 preparation of protein hydrolysates (head, collar, tail and roe portions) 

 would, of course, serve as a potential source for the isolation of many 

 of the amino acids. In addition a few of the visceral organs are rich 

 sources of certain of the amino acids. For example, the protein, salmine, 

 present in salmon milt, is reported to contain, on the dry basis, about 

 88 percent arginine. This, from all accounts, is one of the richest sources 

 of arginine yet examined. The protein of salmon eggs, without doubt, could 

 serve as a good source of all of the "essential" amino acids. 



Percent Composition 



The percent composition of salmon cannery waste in regard to proteins 

 for the subsequent manufacture of amino acids has been presented in detail 

 under the paragraph on proteins. Average values can be found by referring 

 to Table 2. 



Numerous articles are present in the scientific literature reporting 

 on the amino acid content of fish flesh. Pottinger and Baldwin (lO) re- 

 ported the content of the five amino acids arginine, histidine, lysine, 

 tryptophane, and cystine, found in the protein from the edible portions 

 of a number of fishery products. The values for the five amino acids from 

 the protein of various species of salmon are listed in Table 3. 



19 



