Soy protein products having reduced off-flavor and processes for making the same

Abstract

Novel processes for the production of soy protein products, such as soy protein isolates and soy protein flour, having reduced off-flavors are disclosed. One process includes a three step process including extraction utilizing a mixture comprising supercritical carbon dioxide and an organic solvent. The soy protein isolates produced by the processes describe herein are suitable for use in numerous food products, including soymilk.

1 . A defatted protein flour composition comprising from about 50% to about 65% (by weight dry basis) protein and less than about 1.9% (by weight dry basis) fat (by acid hydrolysis). 
     
     
         2 . The composition of  claim 1  wherein the protein is selected from the group consisting of a plant protein, a dairy protein, an egg protein and mixtures thereof, wherein the plant protein is selected from the group consisting of soy protein, pea protein, lupin protein, wheat protein, corn protein, rice protein and potato protein; the dairy protein is selected from the group consisting of casein, sodium caseinate, calcium caseinate, whey protein concentrate and whey protein isolate; and the egg protein is selected from the group consisting of egg white protein and egg yolk protein. 
     
     
         3 . The composition of  claim 2  wherein the protein comprises a soy protein. 
     
     
         4 . The composition of  claim 1  comprising less than about 1.7% (by weight dry basis) fat (by acid hydrolysis). 
     
     
         5 . The composition of  claim 1  comprising less than about 1.5% (by weight dry basis) fat (by acid hydrolysis). 
     
     
         6 . The composition of  claim 4  wherein the protein comprises a soy protein. 
     
     
         7 . The composition of  claim 5  wherein the protein comprises a soy protein. 
     
     
         8 . A process for preparing a protein isolate comprising contacting the defatted soy protein flour composition of  claim 1  with an aqueous solution to produce a protein isolate. 
     
     
         9 . The process of  claim 8  wherein the protein isolate comprises less than about 1.5% (by weight dry basis) fat (by acid hydrolysis). 
     
     
         10 . The process of  claim 9  wherein the protein isolate comprises less than about 1.0% (by weight dry basis) fat (by acid hydrolysis). 
     
     
         11 . The process of  claim 9  wherein the protein isolate comprises a soy protein isolate. 
     
     
         12 . The process of  claim 10  wherein the protein isolate comprises a soy protein isolate. 
     
     
         13 . A process for preparing a defatted protein composition having reduced off-flavors, the process comprising:
 performing an extraction on a full fat protein composition with a fluid comprising supercritical carbon dioxide to produce a first extracted product wherein the ratio of supercritical carbon dioxide to full fat protein composition is about 10:1 to about 90:1 by weight; and   performing an extraction on the first extracted product with a mixture comprising supercritical carbon dioxide and an organic solvent to produce the defatted protein composition wherein the ratio of supercritical carbon dioxide/organic solvent to first extracted product is about 10:1 to about 90:1 by weight.   
     
     
         14 . The process of  claim 13  wherein the full fat protein composition is selected from the group consisting of a plant protein, a dairy protein, an egg protein and mixtures thereof, wherein the plant protein is selected from the group consisting of soy protein, pea protein, lupin protein, wheat protein, corn protein, rice protein and potato protein; the dairy protein is selected from the group consisting of casein, sodium caseinate, calcium caseinate, whey protein concentrate and whey protein isolate; and the egg protein is selected from the group consisting of egg white protein and egg yolk protein. 
     
     
         15 . The process of  claim 13  wherein the full fat protein composition comprises a soy protein. 
     
     
         16 . The process of  claim 13  wherein the ratio of supercritical carbon dioxide to full fat protein composition is about 20:1 to about 60:1 by weight. 
     
     
         17 . The process of  claim 13  wherein the ratio of supercritical carbon dioxide/organic solvent to first extracted product is about 10:1 to about 50:1 by weight. 
     
     
         18 . The process of  claim 13  wherein the temperature of the extraction of the full fat protein composition is from about 35° C. to about 70° C. 
     
     
         19 . The process of  claim 15  wherein the temperature of the extraction of the full fat protein composition is from about 35° C. to about 70° C. 
     
     
         20 . The process of  claim 13  wherein the temperature of the extraction of the first extracted product is from about 50° C. to about 70° C. 
     
     
         21 . The process of  claim 13  wherein the mixture comprising supercritical carbon dioxide and an organic solvent comprises from about 21 wt. % to about 35 wt. % organic solvent. 
     
     
         22 . The process of  claim 15  wherein the mixture comprising supercritical carbon dioxide and an organic solvent comprises from about 21 wt. % to about 35 wt. % organic solvent. 
     
     
         23 . The process of  claim 13  wherein the organic solvent comprises ethanol. 
     
     
         24 . A process for preparing a defatted protein composition having reduced off-flavors, the process comprising performing an extraction on a full fat protein composition with a mixture comprising supercritical carbon dioxide and an organic solvent to produce the defatted protein composition wherein the ratio of supercritical carbon dioxide/organic solvent to full fat protein composition is about 10:1 to about 90:1 by weight. 
     
     
         25 . The process of  claim 24  wherein the ratio of supercritical carbon dioxide/organic solvent to full fat protein composition is about 10:1 to about 60:1 by weight. 
     
     
         26 . The process of  claim 23  wherein the organic solvent comprises ethanol.