Manufacture of protein hydrolysates

Claim 1

IN A PROCESS INVOLVING THE SULFURIC ACID HYDROLYSIS OF A PROTEINACEOUS COMPOSITION, FOLLOWED BY TREATING THE HYDROLYSATE WITH A SUFFICIENT AMOUNT OF AGENT SELECTED FROM THE GROUP CONSISTING OF ALKALINE EARTH METAL OXIDES, HYDROXIDES, AND CARBONATES TO GIVE THE HYDROLYSATE A PH BETWEEN ABOUT 10.5 AND ABOUT 12.0, AND SEPARATING INSOLUBLE MATTER THEREFROM; THE IMPROVEMENTS COMPRISING HEATING THE RESULTANT ALKALINE SOLUTION UNTIL THE VAPOR THEREFROM IS SUBSTANTIALLY FRED FROM AMMONIA, ADDING TO THE RESULTANT SOLUTION ACIDIC MATERIAL SELECTED FROM THE GROUP CONSISTING OF ACIDS AND ACID ANHYDRIDES WHOSE SALTS WITH ALKALINE EARTH METALS ARE SUBSTANTIALLY WATER-INSOLUBLE IN AN AMOUNT SUFFICIENT TO GIVE SAID SOLUTION A PH BETWEEN ABOUT 5.0 AND ABOUT 7.0, SEPARATING INSOLUBLE MATTER COMPRISING INSOLUBLE ALKAINE EARTH METAL SALTS FROM THE ADJUSTED SOLUTION, CONCENTRATING THE RESULTANT SOLUTION BEYOND THE SATURATION POINT OF TYROSINE AND LEUCINE, COOLING THE CONCENTRATE AND SEPARATING SAID CRYSTALLIZED AMINO ACIDS THEREFROM, TREATING THE RESULTANT SOLUTION WITH AN ADDITIONAL AMOUNT OF THE AFORESAID ACIDIC MATERIAL TO GIVE SAID SOLUTION A PH BETWEEN ABOUT 2.5 AND ABOUT 3.5, SEPARATING INSOLUBLE ALKALINE EARTH METAL SALTS FROM THE RESULTANT SOLUTION, CONCENTRATING THE SUBSTANTIALLY ALKALINE EARTH METAL-FREE SOLUTION TO THE SATURATION POINT OF GLUTAMIC ACID, COOLING THE CONCENTRATED SOLUTION, AND SEPARATING CRYSTALLIZED GLUTAMIC ACID THEREFROM.