10 



U.S. BUREAU OF FISHERIES 



A method for packing fish and fillets in an atmosphere of carbon 

 dioxide was developed and the effect of this procedure observed. 

 It was found that, for long periods of shipment, the atmosphere of 

 carbon dioxide had a decided beneficial action both on the bacterial 

 count and on enzyme action. In the case of short periods of ship- 

 ment, the carbon dioxide was not appreciably better than air. It was 

 observed that, in order to obtain full benefit, fish should be placed in 

 an atmosphere containing approximately 25 percent of carbon dioxide 

 gas immediately upon being caught. 



All of the present methods for the determination of water in protein 

 compounds are tedious and require considerable time for completion 

 and the accuracy of most of them is somewhat doubtful. In some of 

 the studies of stored fish it has been necessary to determine the mois- 

 ture content of the flesh at frequent intervals and to a greater degree 

 of accuracy than has heretofore been possible. A method has been 

 developed for this determination which eliminates all of the diffi- 

 culties previously encountered. A period of only a few hours is 

 required for this determination by the new method and the accuracy 

 is far greater than any previously employed. The water combined 

 with the protein is liberated by coagulating the protein with acetone. 

 The water and the acetone are then evaporated leaving only the 

 completely dried protein. It has been possible to obtain results by 

 this method which check within one tenth of 1 percent. 



The following members of the technological staff performed the 

 above-described investigations of the chemistry of the production, 

 handling, preservation, storage, and marketing of fresh and frozen 

 fish: James M. Lemon, Francis P. Griffiths, Maurice E. Stansby, 

 Louella E. Cable, Richard Locke, Francis Yetman, and Donald 

 Bean. These scientific workers are all located in the Division's 

 technological laboratory at Gloucester, Mass. 



IMPROVEMENTS IN THE SMOKING OF FISH 



For the past several years, our Gloucester laboratory has carried 

 out experimental work in the smoking of fish. As described in 

 previous annual reports of this Division, a small model smokehouse was 

 constructed so as to control the various factors affecting the quality 

 of smoked fish such as temperature, humidity, volume of smoke, 

 etc. Finnan haddie of uniformly liigh quality were produced experi- 

 mentally by our technologists. Reports are being prepared for pub- 

 lication on certain completed phases of this work. 



Mackerel were found to yield a smoked product of exceptionally 

 high quality both as to appearance and flavor. The smoke was 

 applied at as low a temperature as possible and in an atmosphere of 

 high moisture content. It is believed that a market for smoked 

 mackerel could be developed which would open a considerable field 

 for the disposal of some of the surplus mackerel at a reasonable 

 profit to the producer. 



METHODS FOR CANNING FISH IN THE HOME 



Because of the great demand from home economics workers of the 

 various counties. States, and of the Federal Government, and due to a 

 large number of inquiries received by this Bureau for methods, safe 

 and satisfactory to the housewife, for canning fish in the home, and 



