ISOLATION OF LOW-MOLECULAR-MASS HYDROPHOBIC BITTER PEPTIDES IN SOYBEAN PROTEIN HYDROLYSATES BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The molecular mass distribution of peptides in isoelectric soluble soybean protein hydrolysates and their hydrophobic peptide fractions was determined by gel permeation HPLC on a Zorbax Bio Series GF-250 column. The hydrophobic bitter peptide fraction of isoelectric soluble soybean protein hydrolysate with degree of hydrolysis 15% was fractionated on a Sephadex G-25 Fine column. The most bitter low-molecular-mass fraction of the peptides was separated by reversed-phase HPLC on a Spherisorb ODS-2 column. Fourteen low-molecular-mass hydrophobic bitter peptides containing three to six amino acid residues were isolated. They are predominantly composed of hydrophobic amino acids and have leucine, valine or tyrosine at their C-terminal position