BACTERIOLOGICAL ANALYSIS OF AN EXPERIMENTAL 

 PACK OF CANNED SALMON' 



By Reginald H. Fiedler 



Seattle, Washington 



It is well known that bacteria cause spoilage of canned salmon. 

 At the present time there is much agitation on the part of salmon can- 

 ners to determine just how long to process salmon in order to kill 

 any bacteria present. When it is remembered that the annual pro- 

 duction of canned salmon on the Pacific Coast exceeds 7,000,000 

 cases, we find the question of grave importance. It requires a longer 

 time to kill certain bacteria than others, as for instance spore-bearing 

 bacteria will withstand a longer process than non-spore-bearing bac- 

 teria. The purpose of this investigation will be to determine the 

 length of time and the temperature of the process necessary to kill 

 certain spore-forming bacteria inoculated in the cans before proces- 

 sing. 



HISTORY 



Much literature has accumulated in the past quarter of a century 

 in regard to the bacteriology of canned foods. However, very little 

 of this scientific investigation touched upon the bacteriology of canned 

 salmon. To throw some light on the present experiment it may be 

 of value to give a short resume of previous efforts along this line. 



The first scientific work in the bacteriology of fisheries products 

 in this country was conducted in 1897 by Prescott and Underwood, 

 who studied the spoilage of canned salmon and lobsters. They sepa- 

 rated several species of bacteria from the samples studied. Inocula- 

 tion with these brought results. They tested retort and water-bath 

 sterilization and found the former to be the better method. 



In 1908 Cathcart, of the Lister Institute, made examination of 

 "blown" sardines. A health ofiicer had rejected these cans as unfit 

 for food. Upon opening, the cans gave ofT a very violent smelling 

 gas. Organisms of the B. coli type were isolated. Feeding these 

 cultures to guinea pigs proved negative. 



Teyxeria, 1910, in Italy, investigated the cause of poisoning 

 thought to be due to spoiled canned fish. He found several kinds of 



1 This experiment was undei taken as a problem in the College of Fisheries. Univer- 

 sity of Washington. The bacteriological work was carried on in the bacteriological 

 laboratory of the University, under the personal supervision of Dr. John Weinzirl, head 

 of the Department, to whom the author is indebted for advice. 



Printed by permission of the College of Fisheries, University of Washington, Seattle. 



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