CANNING OF FISH AND FISH PRODUCTS 



427 



Cans. The entire end of the sanitary can in use is applied after the fiUing is 

 done, and the can is closed by crimping or double-seaming the end to the body, no 

 acid or solder being used except on the side seam. A form of cement or rubber 

 gasket is used to assist in making a tight enclosure. 



The containers are also classed as plain and enamel-lined, the latter type being 

 used for all fish products. The enamel is a "baked on" type, known as seafood 

 formula "C" enamel, and is universally used for fishery products. A few products. 



Operation Rolls 



NARROW ^i 



T=^ 



WIDE 



First 



Second 



(Courtesy L. G. McKee) 



Fig. 20-2. Can sealer rolls ( above ) and sketch of can ( below ) 

 showing different parts. 



such as shrimp, crab meat, some tuna, and fish flakes, are packed in parchment 

 paper-lined cans, in addition to enamel; this prevents the appearance of any 

 dark spots due to contact of the contents with the metal. Wood and other liners 

 have been used, but parchment paper has now superseded all others. Cans which 

 are exported or those which are likely to be exposed to dampness or salt air are 

 generally lacquered to prevent rusting. A great variety of can sizes are in use so 

 that the consumer may get a product in almost any convenient quantity. 



Cleaning and Trimming. In canning fish products cleaning and trimming gen- 

 erally consist of the removal of the head, viscera, and tail fin; the washing of the 

 eviscerated fish to remove blood, etc.; and the trimming of the fish into pieces 

 of proper size to pack into cans. Although in many branches of the industry this 

 work is done by hand, mechanical contrivances have been worked out to a greater 

 or lesser extent in connection with sardine and tuna canning, and have reached 

 a very high degree of perfection in the salmon-canning industry, as will be de- 

 scribed later. 



Brining or Pickling. In order to draw the blood from the tissues of the fish and 

 to give the flesh a proper degree of firmness and a desired flavor, many kinds of 

 fish are held in a strong brine for a varied length of time before and after trimming. 

 The time of holding and the strength of the brine used depend largely upon the 

 size and fatness of the fish and the nature of the subsequent canning operations. 



Cooking. Many fish, salmon being the most notable exception, are subjected to 

 some cooking or drying process before being packed into cans. This removes 



