CHAPTER 19 



The Preservation of Fish by Smoking and Drying 



By C. L. Anderson 



Director, Alaska Department of Fisheries, Juneau, Alaska. 

 Formerly, Assistant Director and Chief Technologist, Wash- 

 ington State Department of Fisheries, Seattle 



and 



R. K. Pedersen 



Technologist, French Sardine Co., Terminal Island, Calif. 



Formerly, Technologist, Washington State Department of 



Fisheries, Seattle. 



An Introduction to Fish Curing 



Destruction of Bacteria and Enzymes 



Since the decomposition or breakdown of fresh fish flesh is primarily due to 

 the action of bacteria and enzymes, the principal consideration in all methods 

 of fish curing is to destroy both of them completely, or, failing in this, to reduce 

 or inhibit the growth of the bacteria and the autolytic action of the enzymes to 

 such a point that spoilage progresses so slowly that the prepared product will be 

 marketable over a reasonable period of time. This may be accomplished in several 

 ways. 



Low Temperatures. Temperatures between 70 and 100° F (21.1 and 37.8° C) 

 seem to be the most favorable for the multiplication of the common putrefactive 

 bacteria. As the temperature is decreased progressively below 70° F (21.2° C), 

 bacterial decomposition is gradually retarded until at points below freezing it 

 ceases entirely for all practical purposes. Enzymatic spoilage is retarded at moder- 

 ate storage temperatures, but becomes negligible only at a very low temperature 

 (-40°F [-40°C]). 



This is the basic principle recognized in the preservation of fish by icing and 

 freezing. In curing fishery products low temperatures are often of value in holding 

 the raw fish before preparation and in subsequent storage after curing; they are 

 used for mild-salted, spiced, pickled, and smoked products. 



High Temperatures. The application of heat will likewise inhibit both putrefac- 

 tion caused by microorganisms and autolysis due to enzymes. When proper tem- 

 perature and length of exposure are utilized, both of these spoilage processes can 

 be completely checked. Canning of fishery products is, of course, the classical 

 example of the use of this principle. In the hot-smoking of certain kinds of fish 

 sufficiently high temperatures are employed so that enzymes are completely in- 



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