CHAPTER 16 

 Refrigeration and Freezing of Fish 



Importance of Refrigeration 



As fish and shellfish are among the most perishable of food products, it is 

 necessary that they be handled in such a way as to retain their "freshness" from 

 the moment of capture to consumption. There are numerous excellent methods of 

 preserving fish, including refrigeration, freezing, canning, salting, drying, smoking, 

 and pickling. However, at temperatures above 32° F (0° C) fish deteriorate so 

 quickly that it is necessary to pack them in crushed ice or otherwise refrigerate 

 them, even though they are to be held for only a short time prior to use or 

 preservation by some other method (e.g., salting or canning). Refrigeration is, 

 therefore, by far the most important and generally used method of preserving 

 fish since it removes them from the class of extreme perishables and permits an 

 extremely variable supply to be stabilized and moved into the market as necessary 

 to meet a highly fluctuating demand. There are few industries which depend 

 more fully on refrigeration than the fish industry. 



This chapter is devoted solely to the refrigeration and freezing of fish. The 

 methods of refrigeration and freezing of shellfish and other fishery products are 

 presented in the chapters in which the technology of the capture and utilization 

 of these products are considered. 



Location and Extent of Industry 



The business of freezing and storing fish is of much greater importance in the 

 United States than in any other country in the world. The American industry is 

 located principally in the New England, Pacific coastal, and Middle Atlantic 

 states, and in Alaska and the Great Lakes region. In New England the principal 

 species frozen are rosefish, whiting, cod, haddock, mackerel, pollock, swordfish, 

 flounder, and herring. In the Middle Atlantic states mackerel, whiting, haddock, 

 cod, and flounder are the species frozen in the greatest quantity. In the South 

 Atlantic and Gulf states mullet, grouper, Spanish mackerel, squeteague, and red- 

 fish are frozen in considerable quantities. On the Pacific Coast salmon, halibut, 

 tuna, smelt, rockfish, black cod, and flounder are the most important. In Alaska 

 halibut and salmon are the principal species frozen. Chubs, lake herring, ciscoes, 

 and lake trout from the Great Lakes are the fresh-water species frozen in greatest 

 quantity. 



Most of the fish are frozen in the late spring, summer, and autumn and held 

 until winter and spring. The maximimi holdings are usually in November and the 

 minimum in March or Aprfl. However, there is some freezing during every month 

 of the year. The quantities of the various fish frozen in the United States and 

 Alaska in 1949 are indicated in Table 86 (pp. 330-331). In this table the pro- 



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