the year salmon cannery waste is not available. Therefore, in order 

 to carry out these tests, it was necessary to use frozen salmon eggs 

 from the previous season's pack. The frozen eggs were thawed; the 

 chemicals added to and thoroughly mixed with the eggs; the mixture was 

 allowed to stand at room temperature for two days; and then the treated 

 eggs were re-frozen and used as needed in the feeding tests. The eggs 

 were re-frozen as a matter of convenience in handling, since the purpose 

 of these feeding tests was not to determine the efficiency of the pre- 

 servatives, but rather to determine whether or not the chemical additives 

 were toxic to the fish. 



Four preservative treatments were tried: 



a. Sodium benzoate, 2 percent, and sodium chloride, 2 percent. 



b. Sodium benzoate, 1 percent; sodium bisulfite, 0.1 percent; 

 and sodium chloride, 2 percent. 



c. Sodium bisulfite, 0.5 percent. 



d. Sodium bisulfite, 0.2 percent, and sodium chloride, 2 percent. 



Commercial-Scale Tests 



During the summer of 1951 a semi-commercial-scale lot of chemically 

 preserved salmon eggs was put up at a cannery in Petersburg, Alaska. In 

 this experiment 5,000 pounds of eggs were preserved with 0.5 percent 

 sodium bisulfite in 30-pound tinned berry cans with friction-top lids. 

 These eggs were then snipped from Petersburg to Seattle by regular commer- 

 cial steamship and transported to the Federal fish natchery at Leavenworth, 

 Washington. When the shipment arrived at Leavenworth the eggs were 

 examined by laboratory personnel and found to be partly liquefied and 

 badly spoiled with a strong hydrogen sulfide odor present. These results 

 were contrarj' to those obtained in the preceeding experiments. An explan- 

 ation for this lack of keeping quality of the treated eggs may lie in the 

 difference in handling the eggs at the plant. At the Petersburg cannery 

 the waste was flumed with sea water; at the other canneries, where the 

 salmon eggs were obtained for the previous year's tests, the eggs were 

 flumed with fresh water. It is possible that enough salt from the sea 

 water penetrated the eggs and peptized the protein, rendering the m?terial 

 more susceptible to spoilage. 



Careful cost records during the 1951 collection showed that salmon 

 eggs preserved with sodium bisulfite (0.5 percent Gy weight of the eggs) 

 could be delivered to Seattle at a cost of 7.15 cents per povind as compared 

 with 7.75 cents per pound required to deliver the eggs to Seattle in a 

 frozen condition (see Part V). 



42 



