Cereal Chem 61:439 - 445. | VIEW
Uniquely Textured Products Obtained by Coextrusion of Corn Gluten Meal and Soy Flour.
P. E. Neumann, B. K. Jasberg, J. S. Wall, and C. E. Walker. Copyright 1984 by the American Association of Cereal Chemists, Inc.
Although nutritionally advantageous, the blending of corn and soy proteins in foods is limited by their distinctly different functional properties. Chemically bonding these proteins by altering their molecular conformation and linking them together through disulfide bonds was explored by means of coextrusion. Wet-milled corn gluten or decolorized corn gluten (DCG), (pH 7.0 and 30-35% moisture) were mixed with a similarly hydrated, untoasted, defatted soy flour (DSF) at different proportions and extruded under the proper conditions to yield textured products. When rehydrated in boiling water, DCG:DSF extruidates possessed poultry white meatlike color and unique meatlike texture but had water-holding capacities (WHC) that were less than that of DSF extrudate. Scanning electron microscopy showed that DCG:DSF extrudates had a more disrupted fiber structure than DSF extrudate. Sequential extraction of protein from DCG, DSF, and 46:54 DCG:DSF extrudate with a series of nonreducing and reducing solvents indicated that intermolecular disulfide bonds were formed during extrusion. Amperometric titration data established that other derivatives of cysteine present in DCG were maintained during coextrusion. Calculated protein efficiency ratios based on in vitro digestibility test and amino acid analyses for 52:48, 46:54, and 40:60 DCG:DSF extrudates were 1.63, 1.76, and 1.97, respectively.