Soy proteins and methods for their production

A process for producing soy protein concentrates and isolates comprising:

• a) in a reaction vessel contacting a soy protein source with a pectinase enzyme in an aqueous solution for a sufficient period of time to allow an enzymatic treatment of the soy protein source to occur;
• b) providing a tubular rigid porous housing, said housing having at least one metallic oxide ultrafiltration membrane secured along the inside surface of said tubular housing;
• c) subjecting the soy protein source of said reaction vessel to an ultrafiltration by pumping said contents into said tubular housing at sufficient pressures to maintain permeability of the ultrfiltration membrane in the range of about 0.04 to about 0.3 gfd, and for a sufficient period of time to create a soy protein containing retentate, and;
• e) diluting said retentate with additional aqueous solution and pumping said diluted retentate into said housing at sufficient pressures to create a second soy protein retentate.

A process for the removal of isofivones form soy protein comprising:

• a) contacting a source of soy protein with one or more enzymes possessing nuclease and phytase activity for a sufficient period of time to allow said enzymes to react with said source of soy protein;
• b) subjecting the soy protein source of step a) to ultrafiltration by passing said soy protein source through a metallic oxide ultrafiltration membrane at sufficient pressures, to maintain a permeability of the ultrafiltration membrane in the range of about 0.04 to 0.3 gallons/square feet/day (gfd), and for a sufficient period of time to create a retentate, containing soy protein;
• c) diluting said retentate with an aqueous solution to form a diluted retenate and passing said diluted retentate through a metallic oxide ultrafiltration membrane, and;
• d) collecting the diluted retentate, from which isoflavones, phytate, and nucleic acids have been removed.

A process for the removal of at least one impurity selected from the group consisting of isoflavones, phytate, and nucleic acids from soy protein comprising:

• a) contacting a source of soy protein with one or more enzymes possessing nuclease and phytase activity for a sufficient period of time to allow said enzymes to react with said source of soy protein;
• b) subjecting the soy protein source of step a) to ultrafiltration by passing said soy protein source through a metallic oxide ultrafiltration membrane at sufficient pressures, to maintain a permeability of the ultrafiltration membrane in the range of about 0.04 to 0.3 gallons/square feet/day (gfd), and for a sufficient period of time to create a retentate, containing soy protein;
• c) diluting said retentate with an aqueous solution to form a diluted retenate and passing said diluted retentate through a metallic oxide ultrafiltration membrane, and;
• d) collecting the diluted retentate, from which isoflavones, phytate, and nucleic acids have been removed.

A process for producing soy protein concentrates comprising:

• a) in a reaction vessel contacting a soy protein source with a pectinase enzyme in an aqueous solution for a sufficient period of time to allow an enzymatic treatment of the soy protein source to occur;
• b) providing a tubular rigid porous housing, said housing having at least one metallic oxide ultrafiltration membrane secured along the inside surface of said tubular housing;
• c) subjecting the soy protein source of said reaction vessel to an ultrafiltration by pumping said contents into said tubular housing at sufficient pressures to maintain permeability of the ultrfiltration membrane in the range of about 0.04 to about 0.3 gfd, and for a sufficient period of time to create a soy protein containing retentate, and;
• e) diluting said retentate with additional aqueous solution and pumping said diluted retentate into said housing at sufficient pressures to create a second soy protein retentate.

A process for producing soy protein isolates comprising:

• a) in a reaction vessel contacting a soy protein source with a pectinase enzyme in an aqueous solution for a sufficient period of time to allow an enzymatic treatment of the soy protein source to occur;
• b) providing a tubular rigid porous housing, said housing having at least one metallic oxide ultrafiltration membrane secured along the inside surface of said tubular housing;
• c) subjecting the soy protein source of said reaction vessel to an ultrafiltration by pumping said contents into said tubular housing at sufficient pressures to maintain permeability of the ultrfiltration membrane in the range of about 0.04 to about 0.3 gfd, and for a sufficient period of time to create a soy protein containing retentate, and;
• e) diluting said retentate with additional aqueous solution and pumping said diluted retentate into said housing at sufficient pressures to create a second soy protein retentate.