title: Sensory-guided identification of N-(1-methyl-4-oxoimidazolidin-2-ylidene)-alpha-amino acids as contributors to the thick-sour and mouth-drying orosensation of stewed beef juice.
abstract: Sensory-guided fractionation of stewed beef juice using ultrafiltration, gel permeation chromatography, PFPP-HPLC, and HILIC combined with analytical sensory techniques led to the identification of the dipeptides beta-alanyl-N-methyl-L-histidine and beta-alanyl-L-histidine, as well as the creatinine derivatives N-(1-methyl-4-oxoimidazolidin-2-ylidene)aminopropionic acid, N-(1-methyl-4-oxoimidazolidin-2-ylidene)aminoacetic acid, and N-(1-methyl-4-oxoimidazolidin-2-ylidene)amino-4,5,6-trihydroxyhexanoic acid as taste modulators in stewed beef juice. Model experiments demonstrated for the first time that the latter three N-(1-methyl-4-oxoimidazolidin-2-ylidene)-alpha-amino acids are formed by Maillard-type reactions from creatinine and reducing hexoses. Quantitative analysis, followed by taste recombination and omission experiments, revealed that subthreshold concentrations of these taste modulators enhance the typical thick-sour and mouth-drying orosensation and the mouthfulness imparted by stewed beef juice, although none of these compounds exhibited any significant intrinsic taste when tasted individually in water.
authors.affiliation: Food Chemistry and Molecular Sensory Science, Technische Universitat München, Lise-Meitner-Strasse 34, D-85354 Freising-Weihenstephan, Germany.
authors.forename: Tessa
authors.initials: T
authors.lastname: Sonntag
authors.forename: Christof
authors.initials: C
authors.lastname: Kunert
authors.forename: Andreas
authors.initials: A
authors.lastname: Dunkel
authors.forename: Thomas
authors.initials: T
authors.lastname: Hofmann
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry; D000818:Animals; D000861:Anserine / Q000032:analysis; D002336:Carnosine / Q000032:analysis; D002417:Cattle; D005591:Chemical Fractionation / Q000379:methods; D005260:Female; D006358:Hot Temperature; D006801:Humans; D048289:Imidazolidines / Q000032:analysis* / Q000737:chemistry; D015416:Maillard Reaction; D008297:Male; D008460:Meat / Q000032:analysis*; D012996:Solutions; D013649:Taste
chemical_list: D000596:Amino Acids; D048289:Imidazolidines; D012996:Solutions; D002336:Carnosine; D000861:Anserine