Quantitative Structure−Activity Relationship Study of Bitter Peptides

Abstract

A database consisting of 224 di- to tetradecapeptides and five amino acids was compiled to study quantitative structure-activity relationships of bitter peptides. Partial least-squares regression-1 analysis was conducted using the amino acid three z-scores and/or three parameters (total hydrophobicity, residue number, and log mass values) as X-variables and bitterness values (log 1/T where T is the bitterness threshold) as Y-variables. Using the three parameters only, significant models (p < 0.001) were obtained describing the entire data set as well as data subsets, except that comprised only of octa- to tetradecapeptides. For data sets comprising different peptide lengths, the models were improved by including the three z-scores at the N-terminal and C-terminal positions. Correlation coefficients for bitterness prediction of 48 dipeptides and 12 pentapeptides were 0.75 (RMSEP = 0.53) and 0.90 (RMSEP = 0.48), respectively. Bulky hydrophobic amino acids at the C terminus and bulky basic amino acids at the N terminus were highly correlated to bitterness.

Learnings from quantitative structure–activity relationship (QSAR) studies with respect to food protein-derived bioactive peptides: a review

“…25 The molecular mass, hydrophobicity, number of amino acid residues in the peptide together with the amino acid descriptors of the 3-z scale were incorporated in a PLSR. The previous physicochemical parameters had a higher inuence on the bitterness than the 3-z scale.…”

Enzymatic hydrolysis of defatted mackerel protein with low bitter taste

“…The bitter taste of protein hydrolysates limits their utilization for human consumption. It is reported that the bitter taste of protein hydrolysates is mainly caused by hydrophobic amino acid residues and oligopeptides, and therefore the specificity of the enzyme used is decisive for the amount of such peptides produced during hydrolysis (Kim and Li-Chan, 2006;Gildberg et al, 2002). As shown in Fig.3c, flavourzyme hydrolysates, a fungal complex of exopeptidases and endoproteases used in the food functionality industry for extensive hydrolysis of proteins, display the least bitter taste in contrast to all the other enzymes.…”

Valorization of Proteins from Co- and By-Products from the Fish and Meat Industry

“…A current drawback with production of protein hydrolysates is the formation of bitter and unpalatable tastes generated during the hydrolysis process. Bitter taste is mainly ascribed to small peptides of less than 1000 Da with hydrophobic and/or aromatic amino acids [65]. Not only the presence of hydrophobic and aromatic amino acids, but also the amino acid peptide sequence is important for the bitter taste intensity.…”