Taste of Proline-containing Peptides

Abstract

In order to investigate the role of the proline residue in the bitter taste of peptides, some oligopeptides containing proline were synthesized and their tastes were evaluated. Proline peptides exhibited bitterness, this aspect being different from hydrophobic amino acids. The most significant role of proline residue in peptide bitterness was dependent on the conformational alternation of the peptide molecule by folding the peptide skeleton due to the imino ring of the proline molecule. It was demonstrated that 2 bitter taste determinant sites were essential for peptide bitterness and that they should be adjacent in the steric conformation of the peptides.