Numerous Compounds Orchestrate Coffee's Bitterness.

Coffee is one of the most consumed hot beverages worldwide and is highly regarded because of its stimulating effect despite having a pronounced bitterness. Even though numerous bitter ingredients have been identified, the detailed molecular basis for coffee's bitterness is not well understood except for caffeine, which activates five human bitter taste receptors. We elucidated the contribution of other bitter coffee constituents in addition to caffeine with functional calcium imaging experiments using mammalian cells expressing the cDNAs of human bitter taste receptors, sensory experiments, and in silico modeling approaches.

Ion-Mobility-Based Liquid Chromatography-Mass Spectrometry Quantitation of Taste-Enhancing Octadecadien-12-ynoic Acids in Mushrooms.

For the accurate quantitation of kokumi-enhancing and bitter-tasting octadecadien-12-ynoic and octadecadienoic acids in chanterelles ( Fr.), a sensitive ultra-high-performance liquid chromatography-differential ion mobility spectrometry-tandem mass spectrometry method was developed. On the basis of these quantitative data and the taste thresholds, dose-over-threshold factors were calculated to determine the contribution of these sensometabolites to the kokumi and bitter taste of chanterelles; e.

Discovery of taste modulating octadecadien-12-ynoic acids in golden chanterelles (Cantharellus cibarius).

Activity-guided fractionation in combination with taste dilution and comparative taste dilution analysis, followed by LC-MS and 1D/2D-NMR experiments, enabled the identification of several C-acetylenic acids in chanterelles among which (9Z,15E)-14,17,18-trihydroxy-9,15-octadecadien-12-ynoic acid, (9Z,15E)-14-oxo-9,15-octadecadien-12-ynoic acid, (10E,15E)-9-hydroxy-14-oxo-10,15-octadecadien-12-ynoic acid, (10E,15E)-9-hydroperoxy-14-oxo-10,15-octadecadien-12-ynoic acid, (10E,15E)-9,14-dioxo-10,15-octadecadien-12-ynoic acid, (9Z,15E)-14-oxo-9,15-octadecadien-12-ynoic acid methyl ester, (9Z,15E)-17(18)-epoxy-14-oxo-9,15-octadecadien-12-ynoic acid methyl ester and (10E,14Z)-9-hydroperoxy-10,14-octadecadien-12-ynoic acid have not yet been reported in literature. Sensory evaluation in a basic taste recombinant revealed taste modulating thresholds for the octadecadien-12-ynoic acids in the range of 19-105 µmol/l. In comparison, three isolated octadecadienoic acids, namely (10E,14Z)-12-hydroxy-10,14-octadecadienoic acid, (9Z,11Z)-14,18-dihydroxy-9,11-octadecadienoic acid, and (9Z,11Z)-14,17,18-trihydroxy-9,11-octadecadienoic acid, respectively, did not show any taste modulating activity, thus pinpointing the putative key role of the acetylene moiety for kokumi enhancement.