CANNING OF FISH AND FISH PRODUCTS 



439 



which air heated by steam coils is drawn by means of a fan. The drying usually 

 occupies from 1 to 2 hours at a temperature from 100-120° F (38 to 49° C). 

 After cooling, the dried fish are carried on the flakes to the packing tables where 

 women remove the heads and pack them in cans; the larger fish, however, are 

 often dressed on arrival at the cannery. 



Oil is then mechanically placed in each can and the cans are passed through 

 the sealing machines which attach the covers. They are then processed or sterilized 



OEWATERINS SCREEN 



CONVEYOFLO METER 

 FISH PASSIM OVER TOTALIZER HEAD 



WEIOH SPAN OF , 



CONVErOFLO METER I 



TO PROCESS OH STORAOE 



(.Courtesy Harry F. R. Dolan, Jr.) 



Fig. 20-8. In many canneries the fish are pumped from the hold of the vessel across a 

 weighing apparatus and into the cannery for processing. 



in a few plants by heating for VA or 2 hours in boiling water. The cans, while hot, 

 are usually cleaned with sawdust, and after cooling are tested for leaks and packed 

 in cases. 



Pressure Sterilization. While some packers still use the hot water method of 

 sterilization, the majority use the more modern pressure method. If the pressure 

 retort method is used, the sealed cans are put in large metal baskets and placed in 

 retorts. When filled the retorts are sealed and dry steam is admitted until a tem- 

 perature of 240° F (116° C) is attained; this is held for 45 minutes. The processed 

 cans are then removed from the retort and washed to cool and remove the ad- 

 hering oil. 



Improvements in the mechanical preparation of sardines have recently been 

 made through the development of a machine for cutting off the heads of the 

 raw fish. However, a machine of similar type has been in use for many years by 

 a large Maine canner, who also uses a continuous form of drier with belt con- 

 veyor. A machine has also been patented for frying the raw fish directly in the 

 cans, but has not yet come into extensive use. 



Two types of machines for separating fish according to size are used to some 

 extent, and such separation is essential in connection with the cutting machine. 

 The first consists of a revolving cylinder constructed of coiled pipes set apart at 

 gradually increasing distances, and the second is a number of inclined rotating 

 rollers, the distance between which gradually increases as the fish pass down 

 along them. 



A considerable quantity of Maine sardines are fried after partial drying of the 

 raw fish. The frying device most used consists of a long iron tank which contains a 



