EPR study of a 'capsule' brewed coffee and its' decaffeinated version

Full text: Ten or fifteen years ago or less, sensory evaluation of a decaff. coffee would easily recognize it from its caffeinated form. With the development of the capsule method of coffee brewing, this is no longer true. Take-home coffee machines for this method are readily available, and give accurate volumes of hot water for the style of coffee required, e.g. short black, long macchiato. Does the EPR signal change with modern decaffeination of particular coffees? A complete coffee and its decaff. version were examined by EPR. The 'solutions' had an accurate same volume, and the filling factor in the spectrometer was the same for both. A Bruker ~3cm. wavelength EPR with a 'super Q' was used at room temperature, with signal averaging employed in detection. The spectrum of the usual Mn²⁺ signal was the same for both samples, and the ratio of the free radical signal to the Mn²⁺ was also the same. Further details will be given in the full MS. (author)