THE TUNA INDUSTRY 



95 



and thermometers. When full, the cookers are closed, except for vents, 

 and steam is turned on to raise the temperature over a period of 15 to 

 30 minutes to 215 to 220°F. 



Cooking time increases with the size of fish and varies with the tech- 

 nique preferred at each plant. ''Eights" weighing some 6 to 10 pounds 



Figure 7.2. Tuna being conveyed from the boat to the weigh house. 

 ( Westgate-California Corporation . ) 



are cooked for 105 minutes and so on up to fish of 100 pounds which 

 require 8 hours or more. 



Cooling. Tuna is normally cooled overnight to firm it and bring the 

 temperature down to a point at which cleaners may handle it. This is 

 usually done by standing in a cooling room in still air. Lassen^^ has 

 shown that the bacterial count, reduced almost to zero in the precook, 

 rises little for 24 hours although forced circulation of the air adds to the 

 increase. Some drying and oxidation and polymerization of the oily sur- 



