Leucine-Rich Peptide Compositions and Methods for Isolation

Abstract

Disclosed are compositions comprising isolated peptides having a leucine content of from about 12 to about 40 weight percent. Also disclosed is a method for isolating leucine-rich peptides from protein sources such as bovine whey and methods of use for these peptides to provide beneficial effects in a human and/or animal such as increasing blood flow, decreasing blood pressure, increasing muscle mass, improving cognitive function, improving cardiovascular function, etc.

What is claimed is: 
     
         1 . A peptide composition comprising peptides having a leucine content of from about 12 to about 40 weight percent and a molecular weight from about 200 to about 4,000, the peptides having been isolated from a protein source by a method comprising the steps of
 a) hydrolyzing the protein in the presence of at least one leucyl aminopeptidase without additional proteases that are not leucyl aminopeptidases to form a protein hydrolysate;   b) deactivating the aminopeptidase(s); and   c) filtering the protein hydrolysate to produce a permeate containing leucine-rich peptides having a leucine content of from about 12 to about 40 weight percent and a molecular weight of from about 200 to about 4,000 in the permeate.   
     
     
         2 . A peptide composition as in  claim 1 , wherein the method comprises the additional step of concentrating the peptides by removing aqueous fluid from the permeate. 
     
     
         3 . The peptide composition of  claim 1  wherein the protein source is chosen from among the group consisting of legumes, fish, meat, milk, blood, egg, corn, wheat gluten, maize, and combinations thereof. 
     
     
         4 . The peptide composition of  claim 1  wherein the protein source is chosen from among the group consisting of bovine milk, bovine whey, whey protein concentrates, whey protein isolates, and combinations thereof. 
     
     
         5 . The peptide composition of  claim 1  wherein the peptides are concentrated by removing aqueous fluid from the permeate.