FISHERY INDUSTRIES OF THE UjSTITED STATES, 19 3 7 181 



made of the experimental packs of canned fishery products to deter- 

 mine which processes produced sterility; bacterial counts are made 

 on samples used in our studies on the development of indices of 

 relative freshness or of decomposition; the use of ultraviolet rays in 

 killing bacteria; determinations of the value of various chemical 

 preservatives in preventing or retarding bacterial spoilage in fishery 

 byproducts; and other miscellaneous bacterial control problems. 



STUDIES OF ULTRAVIOLET RAYS IN KILLING BACTERIA 



Since the reduction of the presence of bacteria in fish is essential to 

 the preservation of fish, any device or method which can be found to 

 bring about this accomplishment is vitally important to the industry 

 and to the consumer. According to information which we have 

 received, resulting from studies made on other food products, the use 

 of ultraviolet light rays has been beneficial in reducing bacteria in 

 milk, meats, bread, etc., and in improving the keeping qualities of 

 these foods. Therefore, late in 1937, our bacteriologists began a study 

 of the effect of these ultraviolet rays in reducing the bacterial count of 

 various fishery products. As a result, we have found that the rays 

 will kill marine bacteria and we hope to work out a practical and com- 

 mercially feasible application of this method in the treatment of fishery 

 products. 



STUDIES IN THE HANDLING OF FRESH OYSTERS 



Late in 1937, at the request of the Oyster Institute of North Amer- 

 ica, and in cooperation with that organization, a program for studying 

 the handling of fresh oysters was undertaken. Louis F. Ortenzio, a 

 member of the Division's technological staff, was assigned to the 

 study of this problem. While this problem has certain chemical 

 aspects, the major portion of the investigation is a bacteriological one. 

 The work has not progressed to a point where recommendations in the 

 improved handling of oysters can be made. 



Briefly, the following experimental procedure is being used. Bac- 

 terial counts to measure the rate of bacteriological decomposition and 

 determinations of the pH to measure the rate of chemical decomposi- 

 tion are being made on commercial shipments of oysters. This may 

 lead to the development of a test for determining the relative freshness 

 of oysters as well as to the development of methods for preventing or 

 retarding spoilage of fresh and frozen oysters. 



PHARMACOLOGICAL STUDIES 



The role of minerals in foods and in feedstuffs for farm animals is 

 becoming of increasing importance. Not only have certain minerals 

 been found to be essential in nutrition, but there is need for a better 

 understanding of other physiological effects they may have on the 

 animal organism. With this in mind, the Bureau has continued its 

 studies on certain minerals, naturally occurring in fishery products. 



THE FLUORINE CONTENT OF FISHERY PRODUCTS 



The fluorine content of foods presents a major problem in nutrition 

 since the discovery that fluorine is responsible for mottled enamel of 

 teeth. Therefore, during 1937, our technological staff undertook a 



80808—38 3 



