Low-viscosity, high-NSI, heat-gelling soy isolates

A method for preparing a dry, undigested, high NSI, heat-settable vegetable protein isolate, said method comprising the steps of;

• (a) extracting water-soluble constituents from an aqueous vegetable proteinaceous material slurry at a pH between 6.5 and 8.0 with an effective amount of sulfurous ions sufficient to measurably reduce the viscosity of the aqueous solution below that level obtained by carrying out the extraction without the sulfurous ion, (b) partitioning substantially all of the water-soluble constituents from the water-insoluble constituents of said extracted slurry to provide a clarified extract, (c) recovering a major weight portion of the extracted water-soluble protein constituents from the clarified extract, (d) dissolving the recovered protein constituents in water to form an aqueous solution thereof, and (e) dehydrating the aqueous solution to provide said dry vegetable protein isolate.

In a food composition comprised of carbohydrate, triglyceride and protein wherein the protein is at least one protein selected from the group consisting of egg albumin and milk caseinate, the improvement which comprises replacing at least a portion of said protein in said composition with a dry vegetable isolate characterized as:

• (a) having an NSI of at least 90, (b) substantially free from vegetable protein hydrolyzates, (c) forming an insoluble gel when reconstituted in water at a 15% by weight protein isolate concentration and heated to 85.degree. C. for 30 minutes, and (d) yielding an aqueous isolate solution viscosity of less than 100,000 cps when reconstituted with water at 22.degree. C. and a 15% by weight (d.s.b.) isolate concentration.

In a method for preparing a food composition comprised of carbohydrate, triglyceride and protein wherein the protein is at least one protein selected from the group consisting of egg albumin and milk caseinate is used to prepare said food composition, the improvement which comprises replacing at least a portion of said protein in said composition with a dry vegetable isolate characterized as:

• (a) having an NSI of at least 90, (b) substantially free from vegetable protein hydrolyzates, (c) forming an insoluble gel when reconstituted in water at a 15% by weight protein isolate concentration and heated to 85.degree. C. for 30 minutes, and (d) yielding an aqueous isolate solution viscosity of less than 100,000 cps when reconstituted with water at 22.degree. C. and a 15% by weight (d.s.b.) isolate concentration.