PREPARATION OF PEPTIDE MIXTURE HAVING LOW PHENYLALANINE CONTENT

摘要

PURPOSE:To provide a peptide mixture having low phenylalanine content and useful as a delicious and easily digestible protein source for the patient of phenylketonuria, economically with a simple process. CONSTITUTION:A peptide mixture having low phenylalanine content can be prepared by (1) the process to obtain a polypeptide almost free from aromatic amino acid and a free aromatic amino acid or a low-molecular weight peptide having aromatic amino acid at the terminal either by treating a protein with an exopeptidase in aqueous system or by treating first with an endopeptidase and then with an exopeptidase; (2) the process to adsorb the free aromatic amino acid or the low-molecular weight peptide having aromatic amino acid at the terminal with activated carbon, and (3) the process to separate the low- molecular weight substances with a reverse-osmosis membrane and/or an ion- exchanging electrodialysis membrane. The obtained mixture is free from the characteristic taste and odor of amino acid and almost free from phenylalanine and low-molecular weight substances.