£52 REPORT OF THE SECRETARY. OF COMMERCE 
a view to making recommendations as to improved methods of han- 
dling and packing for shipment which would assure the public a 
higher quality product. Tentative recommendations were made to 
the crab-meat packers pending the issuance of a completed report. 
Pharmacological studies —As indicated in previous years, the role 
of minerals in nutrition has become increasingly important. Fishery 
products are considered to be an excellent source of minerals in 
quantity and variety, and a better understanding of the physiological 
effects of these minerals on the animal organism is necessary. Dur- 
ing 1938 the Bureau’s technologists completed a study of the chemical 
and pharmacological aspects of fluorine in fishery products. No toxic 
symptoms were observed when the fluorine in the diet came from 
salmon or mackerel. 
Nutritive value of fishery products—During 1938 investigations 
in this field included a study of the chemical composition and nu- 
tritive value of fish proteins, the vitamin content of fishery products, 
a study of sodium alginate (produced from sea kelp) as a stabilizer 
in products of the dairy industry, and a cooperative study of kelp 
meal in animal feeding at the dairy department of the University of 
Maryland and of the Maryland State Agricultural Experiment Sta- 
tion, College Park, Md. 
The studies of the mineral constituents of fishery products showed 
that fish fillets are about equal to the muscle cuts of beef in mineral 
content, except that the fish greatly exceeds the meat in iodine content ; 
that canned salmon contains about 15 times as much calcium, almost 
twice as much phosphorus, 20 times as much iodine, and approxi- 
mately equal quantities of other minerals as beef round; and that 
oysters, shrimp, and crab meat contain approximately half as much 
calcium, more than 5 times as much magnesium, and more phosphorus 
than an equal quantity of milk. In addition, these shellfish are a 
particularly good source of iron, copper, and iodine. 
The results of the studies on the chemical composition and nutri- 
tive value of fish proteins showed that, by using an arbitrary factor 
of 100, the proteins of the following fish and shellfish fell ito the 
following groups according to relative growth-promoting value, as 
compared to beef at a factor of 63: Oysters, 100; pilchard, red snap- 
per, shrimp, and Boston mackerel, 90; and shad, cod, croaker, and 
silver salmon, 80. 
The results of the studies on sodium alginate showed that this 
product is an excellent mechanical stabilizer for use in food products, 
due to its chemical and physical properties and high viscosity value. 
Preservation of fishery byproducts—During the year data have 
been obtained regarding specific problems of salmon cannery waste 
utilization. These include investigation of the suitability of small- 
unit operations for canneries whose outputs are too small to warrant 
installation of standard fish-meal equipment, the preparation of 
edible salmon oils, the preparation of dehydrated protein and vitamin 
concentrates, and in the case of large canneries having short operat- 
ing seasons, the chemical preservation of waste for subsequent re- 
duction and the conversion of waste into new types of products as a 
result of chemical treatment. A survey was undertaken to determine 
the potential vitamin value of the livers and viscera of the principal 
food fish taken commercially on the Pacific coast. In cooperation 
with the Division of Fish Culture and the University of Washington 
