Analytical Methods for the Profiling of Intrinsic Quality of Green Coffee: Varietal and Geographical Characterisation

Coffee green beans of the two commercial coffee varieties, Coftea arabica and C. canephora, from the most important regions producing coffee in America, Africa and Asia were studied. The polyphenolic and methylxanthine contents analysed by liquid chromatography coupled with a UV-visible spectrometry and mass spectrometry, and the isotope ratios of 013c, olsN, 011B determined by elemental analysis isotope ratio mass spectrometry, were measured in coffee green beans. The two analytical approaches proposed were evaluated in order to characterise coffee according to the varietal and geographical origin. Quantitation of chlorogenic acids, cinnamate conjugates and caffeine allowed the varietal characterisation of coffee green beans unequivocally. Polyphenolic profiles and the methylxanthine contents, aswell as the isotope values, enable classification by pattern recognition techniques for identifying coffee geographical origin at the continent level. Polyphenols and methylxanthines achieved 95% of correct classification for African and Asian Robusta coffees, and 94% for American Arabica samples. On the other hand, isotopic measurements achieved the 95% level of hits for American coffees, and 88% for African ones. Collection of higher number of samples should improve these results.JRC.I.5-Physical and chemical exposure