342 



MARINE PRODUCTS OF COMMERCE 



hold it firmly in place as it crosses the knife, which slices off the skin without 

 tearing or pulling apart the fillet. One machine will skin all of the fillets cut by 

 22 to 28 filleters (3000 to 4000 pounds per hour). One man is required to feed 

 large fillets to the machine; two are needed for smaller fillets. 



The machine is also designed to split thick fillets, such as those produced from 

 the Pacific Coast rockfish. As split fillets are of uniform thickness, they are better 



{Courtesy Jensen Equipment Co.) 

 Fig. 16-5. Inlet end of Jensen fish-skinning machine. 



suited for packaging in rectangular packages. Furthermore, they can be cooked 

 more uniformly than the thick fillets (Stansby and Dassow, 1949). 



As the fillets come from the skinning machine, they are spread out on a con- 

 veyor where they are inspected and in some plants are sprayed with chlorinated 

 sea water as they pass to a briner. They are then conveyed in 20 to 120 seconds 

 through a brine containing 3 to 15 per cent salt and a few parts per million of 

 sodium hypochlorite. 



Brining. The lower the concentration of brine used, the longer the period of 

 immersion required to prevent drip. Thus, if a 10 to 15 per cent brine is used, 

 only 20 seconds immersion is required; whereas, if the brine contains only 3 per 

 cent of salt, the brining period may be as long as 2 minutes. 



Pure salt solutions are more effective in preventing drip than brine relatively 

 high in calcium and magnesium salts and sulfates (Tressler and Murray, 1932). 

 Furthermore, fillets treated with pure brine retain their good flavor much longer 

 than those dipped in impure brine. Tarr (1941) concluded that the action of the 

 brine is not purely superficial, but the salt slowly penetrates the tissues causing 

 them to swell and bind the liquid tightly. 



Taylor (1933) suggested the use of an alkaline solution containing nitrites as 



