Studies on flavored peptides. Part I. Bitterness of leucine-containing peptides.

In order to investigate the effect ofleucine residues on the taste ofpeptides, someoligo peptides containing leucine residues were synthesized and their taste was evaluated.The hydrophobicity of leucine residues markedly caused the bitterness of peptides and stronger bitterness was always found when a leucine residue was located at the C-terminus ofpeptides.The possibility of 2 binding sites between the bitter peptides and the bitter taste receptors of the gustation cells was postulated.