Abstract: A method of preparing a refined zein-enriched protein hydrolysate composition and/or a refined zein-depleted protein hydrolysate composition comprising enzymatically hydrolyzing a refined zein-enriched protein composition and/or a refined zein-depleted protein composition that have been separated from a refined, destarched corn gluten meal. The refined zein-enriched protein hydrolysate composition has a protein solubility of from about 15% to about 20% at a pH selected from the group consisting of pH 3.4, pH 7.0, and of both pH 3.4 and pH 7.0. The refined zein-depleted protein hydrolysate composition has a protein solubility of from about 20% to about 35% at a pH selected from the group consisting of pH 3.4, pH 7.0, and of both pH 3.4 and pH 7.0. Alternatively, the refined zein-enriched protein composition and/or the refined zein-depleted protein composition have been separated from a corn protein isolate as described herein. Compositions are also provided.

Abstract: A turkey collagen hydrolysate composition is prepared from turkey collagen sources, wherein the composition has: a protein concentration of from about 80 wt % to 100 wt %; a protein molecular weight distribution wherein from about 80% to 100% of the protein in the turkey collagen hydrolysate composition has a molecular weight of from about 500 to about 15,000 Daltons; a protein solubility of from about 97% to 100% at a pH selected from the group consisting of pH 7.0, pH 3.4, pH 5, and all of pH 7.0, pH 5, and pH 3.4; and a protein amino acid content of 3 to 25 glycine (g/100 g sample), 0.5 to 15 hydroxyproline (g/100 g sample), 1 to 18 proline (g/100 g sample), 0.02 to 4 taurine (g/100 g sample), and 0.05 to 3 tryptophan (g/100 g sample). Methods of preparing turkey collagen hydrolysate compositions are described.

Abstract: A composition and method of preparing a corn protein hydrolysate includes obtaining a corn protein composition having a corn protein concentration of at least about 75 wt %, adding an enzyme to a corn protein suspension containing the corn protein composition at a ratio of from about 1:100 to about 1:20 by weight of enzyme to corn protein, controlling the pH and temperature of the corn protein suspension to hydrolyze the corn protein, and terminating the hydrolysis of the corn protein to provide a corn protein hydrolysate that has solubility of from about 7% to about 37% at a pH selected from the group consisting of pH 7.0, pH 3.4, pH 5, and all of pH 7.0, pH 5, and pH 3.4. The corn protein hydrolysate can be used in a variety of food, feed, beverage, and other applications.