BUREAU OF FISHERIES KIX 



PRESERVATION OF FISHERY PRODUCTS FOR FOOD 



Studies on the preservation of fishery products for food are being 

 directed toward developing standard simplified chemical methods for 

 determining the condition of the flesh of fish as to freshness, age, or 

 stage of decomposition. In addition, efforts are being devoted to 

 establishing a standard procedure for smoking fish whereby a product 

 of uniformly high quality can be prepared. For the latter purpose 

 an experimental smokehouse, which is capable of controlling tem- 

 perature, humidity, volume of smoke, and other variable factors 

 encountered in smoking fish, has been built by the technologists of 

 this bureau. Laboratory tests of smoking fish in this apparatus have 

 shown that a product of uniform high quality can be prepared. 



BACTERIOLOGY OF FISH PRESERVATION 



Bacteria play an important role in the handling, preservation, and 

 storage of fishery products. In order to learn the effect of this role 

 on commercial practice and also to aid with other technological re- 

 search, the bureau during the past year installed a bacteriological 

 unit in its Gloucester laboratory. Research to date has consisted in 

 determining the germicidal effect of smoke on fish, the nature of 

 molds on smoked fish and their prevention, and the bacteriology of 

 fresh and frozen fish. 



PRESERVATION OF FISHERY BY-PRODUCTS 



With the installation of a by-products unit as a part of the techno- 

 logical laboratory at Gloucester, Mass., four by-products investiga- 

 tions of pressing interest to the fishing industry were inaugurated. 



Studies on improved methods of manufacturing fish meal from 

 nonoily fish waste have indicated that high temperatures or lengthy 

 drying periods are detrimental to the finished product. Inasmuch 

 as elimination of one ordinarily results in the increase of the other, 

 a distinct advantage may be expected from the determination of an 

 optimum condition. 



The problems associated with the manufacture of fish flour from 

 fillet waste are similar to those associated with the fish-meal work, 

 except that more refined methods are permissible and must be applied 

 in preparing a product for human consumption. One of the main 

 problems in this connection is to obtain an extremely rapid removal 

 of moisture at low temperature. The initial work on this problem, 

 therefore, has been the development of an apparatus which will dis- 

 perse fish material in a drying medium so that extremely rapid 

 drying can be effected. 



Studies on haddock-liver oils have shown that this oil varies in 

 its natural chemical, physical, and biological properties according to 

 season and habitat of the fish. 



Studies on improving the technical usefulness of fish oils are 

 expected to point out w^hen fish oils, owing to their natural variation, 

 are most nearly fitted for the many uses which can be made of them. 



