Process for isolation of proteins using food grade salt solutions at specified pH and ionic strength
AssigneeGeneral Foods Corporation
InventorsE. Donald Murray, Terrence J. Maurice, Larry D. Barker, Chester D. Myers
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Abstract
Proteins of high functionality and in substantially undenatured form are isolated in high yield from protein sources by extraction of the protein from the source material using a food grade salt solution under controlled conditions, increasing the protein concentration of the resultant extract while maintaining the same salt concentration, and diluting the concentrated protein solution. Protein isolate in the form of protein micelles forms in the aqueous phase and settles to an amorphous sticky, gluten-like protein mass, which may be dried to powder form.
Claims26
A process of preparing a protein isolate, which comprises:
- (a) extracting a protein source material with an aqueous food grade salt solution having an ionic strength of at least about 0.2 and a pH value of about 5 to about 6.8 at a temperature of about 15.degree. to about 35.degree. C. to cause solubilization of protein in said protein source material and form a protein solution;
- (b) increasing the protein concentration of said protein solution while maintaining the ionic strength thereof substantially constant;
- (c) diluting the concentrated protein solution to an ionic strength below about 0.2 to cause the formation of discrete protein particles in the aqueous phase at least partially in the form of protein micelles, and
- (d) settling the protein particles to form a mass of protein isolate at least partially in the form of an amorphous sticky gelatinous gluten-like protein micellar mass.
A process of preparing a protein isolate, which comprises:
- (a) extracting a particulated protein source material selected from the group consisting of cereals, legumes and oil seeds by agitation with an aqueous sodium chloride solution having an ionic strength of about 0.2 to about 0.8 and a pH of about 5.3 to about 6.2 at a temperature of about 15.degree. to about 35.degree. C. for about 10 to about 60 minutes to cause solubilization of protein in said protein source material and form a protein solution containing about 10 to about 100 g/l of protein,
- (b) separating the protein solution from residual solid phase,
- (c) concentrating the separated protein solution by a membrane technique to increase the protein concentration thereof while maintaining the ionic strength substantially constant, said concentration being effected at a volume reduction factor of about 1.1 to about 6.0, as determined by the ratio of the volume of protein solution and the volume of concentrated protein solution,
- (d) passing the concentrated protein solution into a body of water having a temperature below about 25.degree. C. and a volume sufficient to decrease the ionic strength of the concentrated protein solution to a value of about 0.06 to about 0.12 to cause the formation of a cloud of discrete protein micelles in the aqueous phase,
- (e) settling the protein micelles into an amorphous sticky gelatinous gluten-like protein micellar mass, and
- (f) separating the protein micellar mass from the aqueous phase.
A process of preparing a protein isolate, which comprises:
- (a) extracting a protein source material with an aqueous food grade salt solution having an ionic strength of at least about 0.2 and a pH of about 5 to about 5.5 at a temperature of about 15.degree. to about 35.degree. C. to cause solubilization of protein in said protein source material and form a protein solution;
- (b) decreasing the phosphorus concentration in the solubilized protein;
- (c) increasing the protein concentration of said protein solution while maintaining the ionic strength thereof substantially constant;
- (d) diluting the concentrated protein solution to an ionic strength below about 0.2 to cause the formation of discrete protein particles in the aqueous phase at least partially in the form of protein micelles;
- and
- (e) settling the protein micelles to form a mass of protein isolate at least partially in the form of an amorphous sticky gelatinous gluten-like protein micellar mass.
Dependencies are inferred from the claim text.