| 摘要 |
1313053 Preparing fish ASTRA NUTRITION AB 28 May 1971 [4 June 1970] 18134/71 Heading A2U Fish is processed to provide a food for human or animal consumption or to provide a starting material for the preparation of a substantially tasteless, odourless, defatted fish protein, by a method in which fresh fish are laid between carriers 3 on a conveyer belt 2 so that they are cut into pieces transversely to their longitudinal axes by rotary, circular knives 4 and the pieces are then transferred to a tank 5 where they are washed in a countercurrent of water, the contents of the tank being stirred and the pieces emerging at 19 after a residence time in the tank of e.g. 15 to 120 minutes. The pieces are then given a second washing in a rotary drum 6 which has helical guides to convey the pieces towards an outlet 21, and longitudinal slots 7 for the escape of viscera and blood which is collected at 22 below a trough 20 enclosing the lower part of the drum. This washing is effected by spray nozzles 9 fed with tap water or saline water. If saline water is used the pieces may be sprayed with tap water at the discharge end of the drum 6. The pieces are then fed, together with a quantity of tap water, by perforated buckets through an optional buffer tank to the bottom of a steam-jacketed direct steam boiler 10 to the bottom of which steam is introduced, and the contents are stirred by a broken helix 11. Temperature sensors control the steam supply to maintain a final temperature of 92‹ to 95‹C where the contents are discharged to a spillway 23 leading to a device 12 for removing bones, fins, scales &c. and consisting of a rotor coacting with a perforated drum which passes the flesh but retains the bones &c. The now coagulated and deboned material is disintegrated in a homogeniser 13 and passed to a centrifuge 14 which removes water soluble proteins and salts, fat and melanin pigment from the fish skins. Before passing to a press 17, in which more water, fat and water soluble compounds are expressed, and a dryer 18, the material may be passed through a further homogeniser 15, to which water at about 90‹C is added, and a further centrifuge 16. |
