Peptide SY is produced by applying a mixture of peptides obtained by processing
fish meat with a protease to a peptide-adsorbing resin (ODS resin or the like),
eluting this with water, then with a 11 to 18% v/v ethanol aqueous solution and
further with water, and collecting and mixing a latter fraction of the water elution
(1), a fraction of the 11 to 18 % v/v ethanol elution and a fraction of
the water elution (2). Further, peptide SY-MD is produced by isolating only
the fraction of the 11 to 18% v/v ethanol elution. Peptide SY and peptide SY-MD
are both novel peptide mixtures. They not only contain a large amount of blood
pressure-depressing peptide Val-Tyr newly found but also have less bitterness and
are excellent in taste and stability, and can be used as a blood pressure-depressing
agent or as functional foods for inhibiting blood pressure elevation or preventing
blood pressure elevation.
