This document specifies a method for the determination of soluble 16-O-Methylcafestol and 16-O-Methylkahweol content (the sum of free forms and derivatives, e.g. fatty acid esters, henceforth abbreviated as 16-OMD = “diterpenes”) in roasted coffee (beans or ground), using quantitative proton nuclear magnetic resonance spectroscopy (1H-qNMR).
If complying with the experimental parameters described below, this test procedure has been proven for the following mass fraction range:
w16-OMD: 20 mg/kg to 2 000 mg/kg.
The mass fraction range can be expanded by suitable changes of the experimental parameters, e.g. a different weighed portion of ground coffee or the accumulation of more NMR-transients.