1 research outputs found
Metabolites of Key Flavor Compound 2,3,5-Trimethylpyrazine in Human Urine
Pyrazines are among the most important compound class
conveying
the odor impressions “roasty”, “nutty”,
and “earthy”. They are formed by the Maillard reaction
and occur ubiquitously in heated foods. The excretion of metabolites
of the key flavor odorant 2,3,5-trimethylpyrazine, abundant in the
volatile fraction of roasted coffee, was investigated. Based on literature
suggestions, putative phase 1 and phase 2 metabolites were synthesized,
characterized by nuclear magnetic resonance and mass spectroscopy
data and used as standards for targeted, quantitative analysis of
coffee drinkers’ urine using stable-isotope-dilution-ultrahigh-performance
liquid chromatography tandem mass spectroscopy (SIDA-UHPLC–MS/MS).
The analysis of spot urine samples from a coffee intervention study
revealed 3,6-dimethylpyrazine-2-carboxylic acid, 3,5-dimethylpyrazine-2-carboxylic
acid, and 5,6-dimethylpyrazine-2-carboxylic acid were quantitatively
dominating metabolites. Only negligible traces of pyrazinemethanols
(3,6-dimethyl-2-pyrazinemethanol and 3,5,6-trimethylpyrazine-2-ol),
glucuronides ((3,6-dimethylpyrazine-2-yl-)methyl-O-β-D-glucuronide
and (3,5-dimethylpyrazine-2-yl-)methyl-O-β-D-glucuronide), and
sulfates ((3,6-dimethylpyrazine-2-yl-)methyl-sulfate and (3,5-dimethylpyrazine-2-yl-)methyl-sulfate)
were detected