[Relations between structure and bitter taste of amino acids and peptides. II. Peptides and their derivatives (author's transl)].

About 80 peptides and their derivatives were tested for bitter taste. The taste thresholds are in the range of 70-80 muMol/ml (Gly-Val) to 0.01-0.02 muMol/ml (Bacitracin). They are dependent on nature and number of the side chains and on the hydrophobicity of the whole molecule. An estimation of the taste thresholds of all di-and tripeptides with known amino acid composition is possible on the basis of their hydrophobicity. As could be shown recently for bitter amino acids, a polar (electrophilic) and a hydrophobic group are essential requirements for bitter peptides also. This model corresponds to all sensory results, e.g. to the bitter taste of all hydrophobic peptides independent on their sequence and configuration and to the sweet taste of L-aspartyl dipeptide esters.