Laura Brehm, O. Frank, M. Jünger
Nov 11, 2019
Citations
0
Influential Citations
8
Citations
Journal
Journal of agricultural and food chemistry
Abstract
Increasing the thiamine concentration in a respective process flavor yields in a product with a significant higher kokumi activity. S-Plot analysis of the mass spectrometric data revealed beside thiamine itself, 4-methyl-5-thiazoleethanol, S-((4-amino-2-methylpyrimidin-5-yl)methyl)-L-cysteine, N-((4-amino-2-methylpyrimidin-5-yl)methyl)¬formamide, 3-(((4-amino-2-methyl¬pyrimidin-5-yl)methyl)thio)-5-hydroxypentan-2-one and 2-methyl-5-(((2-methylfuran-3-yl)thio)methyl)pyrimidin-4-amine as marker molecules for a process flavor with higher thiamine concentration. Sensory based targeted isolation revealed that S-((4-amino-2-methylpyrimidin-5-yl)methyl)-L-cysteine, 3-(((4-amino-2-methyl¬pyrimidin-5-yl)¬methyl)¬thio)-5-hydroxypentan-2-one and 2-methyl-5-(((2-methylfuran-3-yl)thio)methyl)¬pyrimidin-4-amine showed an influence on the kokumi taste activity with taste threshold concentrations between 35 to 120 µmol/L. An adapted mass spectrometric based carbon modul labeling (CAMOLA) experiment as well as quantitative studies clearly demonstrated thiamine as the only precursor and an intermolecular formation pathway for the compounds S-(((4-amino-2-methylpyrimidin-5-yl)¬methyl)¬thio)-5-hydroxypentan-2-one and 2-methyl-5-(((2-methylfuran-3-yl)thio)methyl)¬pyrimidin-4-amine. Based on the knowledge that several thiamine derivatives showed taste modulating activity, selected thiamine-based binary model reactions and synthesis were carried out. This resulted in the isolation of further thiamine derived taste modulators like S-((4-amino-2-methylpyrimidin-5-yl)methyl)-L-cysteinylglycine, (S)-3-((((4-amino-2-methylpyrimidin-5-yl)methyl)thio)¬methyl)¬piperazine-2,5-dione, 3-(((4-amino-2-methylpyrimidin-5-yl)methyl)thio)¬pentan-2-one, 5-(((furan-2-ylmethyl)thio)methyl)-2-methylpyrimidin-4-amine, (4-amino-2-methylpyrimidin-5-yl)methanethiol, 2-methyl-5-((methylthio)methyl)pyrimidin-4-amine with taste thresholds ranging from 35 to 880 µmol/L.