597836 disclose a kind of production soy protein products and protein content is at least 60 weight % (N x 6.25) plate, it includes: to extract in soy protein source and aqueous salt solution optionally comprising antioxidant, is at least 1 °C in temperature to cause the soybean protein soybean protein source of dissolution and forms protein aqueous solution protein content 5 to 50, pH 1.5 to 11, isolate protein aqueous solution and residual soybean protein source, it is 15 to 85 milliseconds to the conductivity of protein aqueous solution that calcium salt soln, which is added, to cause to precipitate the concentrated protein solution with formation, remove sediment and concentrated protein solution, dilution clarification concentrated protein solution enter 2 to 20 volume of water in 2 ° to 90 °C of temperature, be acidified obtained solution to pH be 1.5 to 50, clear protein solution is acidified with production, increases the clear protein solution of acidification of concentration to 51 to 52 g/L, ionic strength substantially constant is kept simultaneously, it the use of retaining molecular weight is 53 to 54 dalton, to provide the second concentrated protein solution with selective film technology.
