Production of soluble protein solutions from soy ("s701")

A soy protein product having a protein content of at least about 60 wt % (N×6.25) d.b. which is substantially completely soluble in an aqueous medium at a pH of less than about 4.4.

A soy protein product having a protein content of at least about 60 wt % (N×6.25) d.b. which is substantially completely soluble in an aqueous medium at a pH of about 7.

A soy protein product which has a protein content of at least about 60 wt % (N×6.25) d.b. which has a solubility at 1% protein w/v in water at a pH of about 2 to about 4 of greater than about 95%, as determined by the methods described in Example 14.

A soy protein product having a protein content of at least about 60 wt % (N×6.25) d.b. which has an absorbance of visible light at 600 nm (A600) in a 1% protein w/v aqueous solution at a pH of about 2 to about 4 of less than about 0.150, as determined by the method described in Example 15.

A soy protein product having a protein content of at least about 60 wt % (N×6.25) d.b. which has a haze reading for a 1% protein w/v aqueous solution at a pH of about 2 to about 4, of less than about 15%, as determined by the method described in Example 15.

A soy protein product having a protein content of at least about 60 wt % (N×6.25) d.b. which has a haze reading for a 2% protein w/v aqueous solution after heat treatment at 95° C. for 30 seconds of less than 15%, as determined by the method described in Example 16.

A process for the preparation of a soy protein solution, which comprises:

• (a) extracting a soy protein source with an aqueous calcium salt solution 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, and
• (c) adjusting the pH of the aqueous soy protein solution to a pH of about 1.5 to about 4.4 to produce an acidified clear soy protein solution.