FISHERY INDUSTRIES OF THE UNITED STATES, 193 7 177 



firm for the purpose of designing an apparatus which could be used 

 commercially and which would enable an operator to make a greater 

 number of tests simultaneously. Mr. Stansby was engaged in this 

 cooperative detail from July 15, 1937, until the end of the year and, as 

 a result of this work, designed equipment which can make determina- 

 tions upon 10 samples of fish at one time. Thus, it is possible for the 

 firm to make very rapid tests for the freshness of fish purchased, by 

 meaiis of this new apparatus, without delaying their pacldng activities. 

 Ordinarily, 15 to 30 minutes w^ere required for testing one sample. 

 However, with the new apparatus, it is now possible for the operator 

 to run the 10 samples in the same length of time and the test is now 

 rapid enough to be used in the ordinary commercial control laboratory. 

 The design of the apparatus is also quite simple and it is easy to manip- 

 ulate. After a little practice an operator, without advanced scientific 

 training, can obtain excellent results. At the present time this equip- 

 ment is being used by the firm, in whose laboratories it was developed 

 on a commercial basis, for the selection of fish which are to be used in 

 packs of frozen products. 



STUDIES OF RANCIDITY IN FISH 



For the past several years we have studied the causes of rancidity 

 in various fishery products and have worked on methods for its pre- 

 vention which might have promise of commercial application. This 

 work has been done in cooperation with the Musher Foundation, 

 Inc., New York City, by research associates employed by the Founda- 

 tion and stationed in our laboratories both at College Park, Md., and 

 Seattle, Wash. 



Several phases of this work which were conducted at our laboratories 

 at College Park and which were described in last year's report, were 

 completed and the results published in the following reports: "Oat 

 Flour as an Anti-oxidant in the Salt Mackerel Industry," by J. M. 

 Lemon, M. E. Stansby, and C. E. Swift, Food, vol. 6, No. 71, pages 

 441-443, August 1937^, 33 Tothih St., Westminster, London, S. W. 1, 

 and Food Industries, vol. 9, No. 10, October 1937, McGraw Hill 

 Publishing Co., New York, N. Y. 



Other phases of this work were conducted in our Seattle laboratory 

 where studies were made by the research associate of the Foundation 

 of the effectiveness of cereal flours and cereal flour extracts in prevent- 

 ing the development of rancidity and the destruction of vitamin A in 

 fish oils and fish liver oils, and the usefulness of these materials in 

 preventing deterioration in other preserved fishery products. As a 

 result of this work, it was found that cereal flours and their extracts 

 have a mild antioxidant action on these products. In the case of 

 fish oils and fish liver oils the eflect was due to retarding the rate of 

 oxidation rather than preventing it for any extended period. In the 

 case of the vitamin active oils, vitamin A destruction corresponded 

 with autocatalytic oxidation; therefore, the cereal flours did not ma- 

 terially increase the period before destruction began but decreased the 

 rate of destruction. On the basis of organoleptic examination, treated 

 oils appeared to be less rancid than untreated oils w^ith a similar degree 

 of oxidation as shown by the peroxide test. 



When cereal flours wore (histed on (h'cssed sahnon or sardines just 

 prior to canning, or the extracts were sprayed on the fish or in the can. 



