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

Abstract

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.In recent years, the remarkable progress in protein chemistry has led to advances in food science. Technology for the isolation of flavored peptides from natural sources, and their structural determination and chemical synthesis was very limited in the past but the recent advances in protein chemistry greatly increased its progress. More than one thousand species of flavored peptides have been identified. Their chemical structures, and the properties and intensities of their taste were also determined. Bitter peptide components were isolated from fermented foods, such as ripened cheese, sake, natto and cocoa,1~4) and from enzyme hydrolysates of protein.5~7) Aspartame (Asp-Phe-OMe) was discovered by Mazur et al.8) as a sweetening agent, and a salty peptide (Orn-Tau) was synthesized in the authors' laboratory.9) At present, flavored

Effect of sequential hydrolysis with endo- and exo-peptidase on bitterness properties of wheat gluten hydrolysates

“…The polyleucines were more bitter than expected from the number of Leu residues present in the Leu oligomers concerned. 10 The same phenomenon extended to phenylalanine (Phe) and tyrosine (Tyr). 11 Interestingly, the positions of hydrophobic amino acids in the peptide chain greatly impacted the bitter taste threshold of the peptide.…”

Bitter Taste Inhibiting Agents for Whey Protein Hydrolysate and Whey Protein Hydrolysate Beverages

“…Many parameters impact bitter taste intensity of a peptide, from the native protein sequence itself, peptide sequences, to the processing/enzymatic treatment steps. Hydrophobicity also plays a major role in bitter taste (Ishibashi and others 1987a, 1988a). Other parameters such as degree of hydrolysis, concentration and location of bitter taste residues, number of carbons on the R group of branched chain amino acids, and conformation of amino acids have been associated with bitterness of peptides (Shinoda and others 1985; Ishibashi and others 1987a, 1987b, 1988a, 1988b; Ohyama and others 1988).…”

Convenient Synthesis of l-Ornithyltaurine·HCl and the Effect on Saltiness in a Food Material

“…Scale ++ indicates that the quality is a little inferior to that of traditional soy sauce. The procedure for the sensory analysis was described in our previous paper (Ishibashi et al, 1987) in detail.…”