226 U. S. BUREAU OF FISHERIES 
to determine optimum amounts of the Carblex to add to the raw 
material and the best way to incorporate it. The above three phases 
of this study were conducted at the College Park (Md.) Laboratory. 
Additional studies on the use of antioxidants for retarding deteri- 
oration of fishery products taken on the Pacific coast were continued 
at the Seattle (Wash.) Laboratory, also under the sponsorship of the 
Musher Foundation of New York. Here attention was given to the 
effectiveness of the various types of water extracts of oat flour, 
“Avenized” salt (a mixture of oat flour and salt), and Carblex in 
retarding oxidation of frozen or mild-cured salmon. It appears from 
this work that the water extracts and the mixtures of oat flour showed 
little effectiveness in improving the keeping quality of frozen salmon. 
However, brine containing the water extract of oat flour was found 
to retard protein and oil decomposition of mild-cured salmon to some 
extent. 
CHEMICAL PRESERVATIVES 
During most of the year three industrial fellows were maintained 
at the College Park Laboratory by the Aquacide Company of Wash- 
ington, D. C. The research has dealt mainly with the development 
of chemical preservatives, both liquid and dry powder, for the preser- 
vation of fish bait and of fish livers prior to extraction of oil. Trials 
under practical conditions have shown that properly preserved livers 
could be held for weeks or even months without refrigeration and 
still yield a medicinal grade of oil. 
A chemically treated fillet wrapper has also been developed which 
improves the quality and prolongs the keepmg time of freshly cut 
fish fillets. In commercial practice, the coated wrapper has promise 
of eliminating the need for brine tanks and permitting more sanitary 
handling of fillets. 
These fellowships were discontinued by the sponsors on December 
31, 1939. The results of the investigations conducted by the indus- 
trial fellows assigned to these problems are being assembled for 
publication. 
MANUFACTURE OF FISHERY BYPRODUCTS 
Studies in this field cover the utilization of the various byproducts 
of the fisheries, and methods for testing and improving their quality. 
UTILIZATION OF SALMON CANNERY TRIMMINGS 
Because of the potential economic value of salmon-cannery trim- 
mings now being discarded in Alaska, the Bureau has continued its 
studies to determime means for attainmg more complete utilization 
of these materials. During the year Fishery Investigational Report 
No. 40, ‘Pacific Salmon Oils” was published and the information 
contained therein was made available to the public. This report 
supples data regarding the chemical and physical properties of 
salmon oils, which are suggestive of their utility fer technical con- 
sumption, and demonstrates conclusively the value of salmon oils as 
sources of vitamins A and D. It is significant that during the year 
a quantity of Alaska salmon oil was, for the first time to our knowledge, 
sold in commercial quantity on the basis of its vitamin potency. 
The value of the Bureau’s investigations on salmon-cannery trim- 
mings becomes more in evidence with each passing year, as waste 
