Benchtop (60 MHz) proton NMR spectroscopy for quantification of 16-O-methylcafestol in lipophilic extracts of ground roast coffee

Graphical exploration of 600‐ and 60‐MHz proton NMR spectral datasets from ground roast coffee extracts

“…The presence of canephora in a blend is betrayed by its aftertaste, described as ‘peanutty’, 23 although the limit of detection even by trained sensory experts is around 15% w/w. Analytical tests developed using NMR can perform substantially better than this, 24–27 down to detection limits commensurate with ‘adventitious contamination’ 28,29 : very low amounts of adulteration arising from some kind of mistake during transport or processing rather than deliberate fraud.…”

“…The presence of canephora in a blend is betrayed by its aftertaste, described as 'peanutty', 23 although the limit of detection even by trained sensory experts is around 15% w/w. Analytical tests developed using NMR can perform substantially better than this, [24][25][26][27] down to detection limits commensurate with 'adventitious contamination' 28,29 : very low amounts of adulteration arising from some kind of mistake during transport or processing rather than deliberate fraud. Spectra of complex biological samples such as coffee invariably contain large numbers of peaks, typically in the hundreds, and the dynamic range of the spectral intensities is such that the largest resonances dwarf the smallest by orders of magnitude.…”