Esterified 16-O-methylcafestol is present in ground roast Arabica coffees: implications for authenticity testing

Gunning Y., Defernez M., Watson A. D., Beadman N., Colquhoun I. J., Le Gall G., Williamson D., Davis A. P., Kemsley E. K., Philo M., Garwood H.. (2017)

Food Chemistry, 248, 52-60

This work reports on improvements on our previous protocol for addressing issues of authenticity in ground roast coffees, using either low or high-field NMR spectroscopy. This is achieved by obtaining a more concentrated extract of the lipophilic fraction. Small but non-negligible quantities of esterified 16-O-methylcafestol (16-OMC-e) were detected in Arabica coffees, whereas it was previously assumed absent from Arabicas and used as a marker for detecting adulteration with other coffee species. Improvements to the protocol allowed robusta in Arabica to be detected at levels of the order of 1% w/w. A surveillance study of retail purchased "100% Arabica" coffees found that 6 out of 60 samples contained 16-OMC-e in amounts commensurate with adulteration at levels of 3 - 30% w/w.

Food Chemistry, 248, 52-60

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