Abstract
Recent investigations on the bitterness of coffee as well as 5-O-caffeoyl quinic acid roasting mixtures indicated the existence of another, yet unknown, bitter lactone besides the previously identified bitter compounds 5-O-caffeoyl-muco-γ-quinide, 3-O-caffeoyl-γ-quinide, 4-O-caffeoyl-muco-γ-quinide, 5-O-caffeoyl-epi-δ-quinide, and 4-O-caffeoyl-γ-quinide. In the present study, this orphan bitter lactone was isolated from the reaction products generated by dry heating of 5-O-caffeoylquinic acid model, and its structure was determined as the previously unreported 3-O-caffeoyl-epi-γ-quinide by means of liquid chromatography-mass spectrometry (LC-MS) and one-/two-dimensional NMR experiments. The occurrence of this bitter lactone, exhibiting a low bitter recognition threshold of 58 μmol/L, in coffee beverages could be confirmed by LC-MS/MS (negative electrospray ionization) operating in the multiple reaction monitoring mode.
| Original language | English |
|---|---|
| Pages (from-to) | 9581-9585 |
| Number of pages | 5 |
| Journal | Journal of agricultural and food chemistry |
| Volume | 56 |
| Issue number | 20 |
| DOIs | |
| State | Published - 22 Oct 2008 |
Keywords
- 5-O-caffeoylquinic acid
- Bitter taste
- Caffeoyl quinides
- Chlorogenic acid
- Coffee
- Lactones