Authentication of Coffee Blends by 16-O-Methylcafestol Quantification Using NMR Spectroscopy

In 2019, a coffee chain in Taiwan was found to be mixing relatively cheap Robusta beans into products marketed as 100% Arabica. Many studies show 16-OMC is remarkable marker distinguish from Arabica beans, and nuclear magnetic resonance (NMR) convenient efficient technique for quantification. Here, 500 MHz NMR employed determine the content of adulterate evaluation. A total 118 samples were analyzed including chain, raw materials (single beans), other commercial products. The contents single between 1005.55 3208.32 mg/kg absent beans. surveillance results indicate that 17 out 47 blend claiming contain had quantifications range 155.74–784.60 mg/kg. Furthermore, all produced by same chain. We confirmed adulterated with parts their products, which claimed include Moreover, this work highlights free form esterified instantly. decomposition observed obviously green while mechanisms remain unclear. Future research should focus more on these aspects further increase our understanding mechanisms.