Analysis of taste-active compounds in an enzymatic hydrolysate of deamidated wheat gluten.
Hydrolyzed plant proteins are widely used as ingredients in culinary products for their glutamate-like ("umami") taste. Three hydrolysates were prepared from wheat gluten using different enzymatic approaches. Comparison of their taste profiles revealed the enzymatic hydrolysate of an acid-deamidated wheat gluten (WGH-3) to be the least bitter of all and to elicit an intense glutamate-like taste. Its umami taste intensity was similar to that of an enzymatic hydrolysate in which glutaminase had been employed to convert free glutamine to glutamic acid and which had a 3-fold higher concentration of free glutamate. Reconstitution studies based on the results of the chemical analysis of WGH-3 and sensory comparison of the model solution and WGH-3 indicated that other components in addition to glutamate and organic acids contribute to its glutamate-like taste. WGH-3 was fractionated by gel permeation chromatography and reversed phase high-performance liquid chromatography, and two fractions with a pronounced glutamate-like taste were obtained. In one of them four pyroglutamyl peptides were tentatively identified: pGlu-Pro-Ser, pGlu-Pro, pGlu-Pro-Glu, and pGlu-Pro-Gln. Apparently, these peptides were formed by cyclization of the N-terminal glutamine residues during the preparation of the hydrolysates.
Schlichtherle-Cerny
Hedwig
H
Institute of Food Science, Swiss Federal Institute of Technology, ETH Zentrum, CH-8092 Zurich, Switzerland. hedwig.schlichtherle-cerny@rdls.nestle.com
Amadò
Renato
R
D000328:Adult; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D010450:Endopeptidases / Q000378:metabolism; D018698:Glutamic Acid / Q000032:analysis / Q000378:metabolism; D005972:Glutaminase / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D005983:Glutens / Q000737:chemistry*; D006801:Humans; D006868:Hydrolysis; D008875:Middle Aged; D009842:Oligopeptides / Q000032:analysis; D013649:Taste; D014908:Triticum / Q000737:chemistry*
D009842:Oligopeptides; D005973:Glutamine; D018698:Glutamic Acid; D005983:Glutens; D010450:Endopeptidases; D005972:Glutaminase