CANNING OF FISH AND FISH PRODUCTS 



451 



Pet Food. A considerable quantity of waste material from the fillet-cutting in- 

 dustry is prepared as pet food. This material consists of the backbone with adher- 

 ing flesh, trimmings from the fillets, and in some instances the heads of the fish. 



HEADING, GUTTING. 

 AND TAKING OUT ROE 



CUTTER 



HAND FILLING TABLE 



FISH TRIMMED INTO 

 CAN LENGTH PORTIONS 



EACH PORTION WRAPPED IN 



PARCHMENT PAPER AND FILLED INTO CANS 



BRINE SPRAY 



OVERHEAD BRINE TANK 



SINGLE TRACK 

 EXHAUST BOX 



CLOSING AND 

 SEALING MACHINE 



VERTICAL RETORTS 



CASING 



-oCl 



LABELLING 



Fig. 20-11. Flow sheet for tlie canning of river herring. 



It is boiled in large kettles, passed through a meat grinder, and mixed with several 

 other ingredients in order that it may be a well-balanced food. These ingredients 

 consist of fish, 30 to 35 per cent; cereal, 30 to 35 per cent; vegetable, 10 per cent; 

 dried milk, 2/2 to 3 per cent; cod-liver oil; and yeast. The whole is thoroughly 

 mixed, placed in No. 1 cans, and processed. Each packer has developed his own 

 particular recipe, which is usually considered secret. The bones are softened dur- 

 ing processing, and furnish calcium and phosphorus. 



