Patent ID: 8557321

Claim:
A process of producing a soy protein product having a soy 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 calcium salt solution at a pH of about 1.5 to about 5.5 to cause solubilization of soy protein from the soy protein source and to form an aqueous soy protein solution, (b) separating the aqueous soy protein solution from residual soy protein source, (c)following said separation step, adjusting the pH of the aqueous soy protein solution to a different value within the range of about 1.5 to about 5.0, (d) concentrating said soy protein solution while maintaining the ionic strength thereof substantially constant to produce a concentrated soy protein solution having a protein concentration of about 50 to about 300 g/L and the concentrated soy protein solution is optionally diafiltered, and (e) drying said concentrated and optionally diafiltered soy protein solution.