Patent GB-758445-A (GB)
Title: Improvements in the manufacture of protein filaments
Inventor: DEVEY JAMES DUNBAR
IPC: A23J3/28
Filed: 1953-02-13
Abstract: Protein filaments are manufactured by extruding a solution of an animal or vegetable protein into an acid coagulating bath to form a bundle of filaments, the acid containing bundle of filaments, which have not been insolubilized to an extent which makes them indigestible by human beings, being treated with an aqueous solution of a carbonate or a bicarbonate.  The gas which is generated when the carbonate or bicarbonate solution and the residual acid on the filaments react causes the filaments to splay out and thus facilitates the penetration of the solution to the inside of the bundle.  The bundles are therefore preferably left slack and relaxed during the treatment.  The carbonate or bicarbonate may be of an alkali metal or ammonium, sodium bicarbonate being preferred in a concentration up to about 5 per cent and preferably 1-3 per cent. The alkaline solution may contain a neutral salt, such as sodium chloride to reduce any tendency for the filaments to dissolve.  The treating temperature is preferably 15-30 DEG  C.  Very preferably the filaments are strengthened prior to the carbonate or bicarbonate treatment, e.g. by immersion in an aqueous solution of an acid and a salt. In an example an alkaline solution of groundnut protein is extruded through a spinneret into a coagulating bath at 25 DEG  C. comprising an aqueous solution containing 12 per cent by weight of sodium chloride, 2 per cent of acetic acid and about 0.7 per cent of sodium acetate.  The bundle of filaments thus formed is passed through a strengthening bath similar in composition to the coagulating bath but maintained at 60 DEG  C. and the filaments simultaneously stretched to double their initial length.  The filaments are then cooled by immersion for one minute in a 5 per cent sodium chloride solution at room temperature, passed through squeeze rollers and fed into a stream of a solution of one per cent sodium bicarbonate and 5 per cent sodium chloride in water at 22.5 DEG  C. flowing under gravity through a sloping glass tube at a rate of 20 litres per minute, the filaments passing through the tube in 25 seconds.  The filaments are rinsed in water in a second glass tube and passed through squeeze rollers.  The filaments may be used in food products.ALSO:Edible protein filaments are manufactured by extruding a solution of an animal or vegetable protein into an acid coagulating bath to form a bundle of filaments, the acid containing bundle of filaments, which have not been insolubilized to an extent which makes them indigestible being treated with an aqueous solution of a carbonate or a bicarbonate.  The gas which is generated when the carbonate or bicarbonate solution and the residual acid on the filaments react causes the filaments to splay out and thus facilitates the penetration of the solution to the inside of the bundle.  The bundles are therefore preferably left slack and relaxed during the treatment.  The carbonate or bicarbonate may be of an alkali metal or ammonium, sodium bicarbonate being preferred in a concentration up to about 5 per cent and preferably 1-3 per cent. The alkaline solution may contain a neutral salt, such as sodium chloride, to reduce any tendency for the filaments to dissolve.  The treating temperature is preferably 15 DEG -30 DEG C.  Very preferably the filaments are strengthened prior to the carbonate or bicarbonate treatment, e.g. by immersion in an aqueous solution of an acid and a salt. In an example, an alkaline solution of groundnut protein is extruded through a spinneret into a coagulating bath at 25 DEG C. comprising an aqueous solution containing 12 per cent by weight of sodium chloride, 2 per cent of acetic acid and about 0,7 per cent of sodium acetate.  The bundle of filaments thus formed is passed through a strengthening bath similar in composition to the coagulating bath but maintained at 60 DEG C. and the filaments simultaneously stretched to double their initial length.  The filaments are then cooled by immersion for one minute in a 5 per cent sodium chloride solution at room temperature, passed through squeeze rollers and fed into a stream of a solution of one per cent sodium bicarbonate and 5 per cent sodium chloride in water at 22,5 DEG C. flowing under gravity through a sloping glass tube at a rate of 20 litres per minute, the filaments passing through the tube in 25 seconds.  The filaments are rinsed in water in a second glass tube and passed through squeeze rollers.