Patent ID: 8404299

Claim:
A process of producing a soy protein product haying a protein content of at least about 60 wt % (N×6.25) on a dry weight basis, which comprises: (a) extracting a soy protein source with an aqueous salt solution at a pH about 1.5 to about 5 to cause solubilization of soy protein from the soy protein source and to form an aqueous soy protein solution, (b) at least partially separating the aqueous soy protein solution from residual soy protein source, (c) concentrating the soy protein solution while maintaining the ionic strength thereof substantially constant to produce a concentrated soy protein solution haying a protein concentration of about 50 to about 300 g/L, (d) pH adjusting the concentrated soy protein solution to a pH of about 1.5 to about 7.0 to form a pH adjusted concentrated soy protein solution, (e) diluting the pH-adjusted concentrated soy protein solution to form a precipitate, (f) separating the precipitate from the supernatant thereto, and (g) drying the separated precipitate or solubilizing the separated precipitate in water at low pH to form a protein solution.