Patent ID: 7705116

Claim:
A recirculating method of solubilizing protein and destroying prions comprising the following steps in the following order: first, applying an alkali to an untreated protein source to form a slurry, wherein the alkali is added in an amount sufficient to induce hydrolysis of the protein source when the slurry is heated; second, heating the slurry to a temperature sufficient to allow hydrolysis of protein in the protein source to obtain a reaction liquid comprising small peptides and free amino acids, and further comprising solid residues; third, holding the reaction liquid at an elevated temperature between 125-250° C. for a time period sufficient to destroy prions in the reaction liquid; fourth, separating the solid residues from the reaction liquid; fifth, neutralizing the reaction liquid with acid or an acid source to produce a neutralized liquid comprising small peptides and free amino acids; sixth, concentrating the neutralized liquid to produce concentrated liquid comprising small peptides and free amino acids and water; and seventh, returning the water to the slurry before or during the heating step.