3,4-dimethoxycinnamic acid levels as a tool for differentiation of Coffea canephora var. robusta and Coffea arabica

Thirteen green Coffea canephora var. robusta and seven green Coffea arabica coffee beans from different geographical origins were analysed by HPLC/diode-array detector for hydroxycinnamic acids (HCAs) discrimination and quantification to assess the possible markers for their botanical and geographical origins. While the HCAs, p-coumaric, o-coumaric and 3,4-dimethoxycinnamic acids were detected in the majority of samples, caffeic and ferulic acids were present in all of them. Sinapic and 4-methoxycinnamic acids were found in only one sample from Mexico and Honduras, respectively. In spite of the preliminary nature of this study, it seems that the relative amount of the HCAs could be related to the botanical origin of coffee. In fact, Coffea canephora var. robusta contains a higher level of 3,4-dimethoxycinnamic ((X) over bar +/- SD:0.433 +/- 0.15, ranging from 0.237 to 0.691 g kg(-1)) than the Coffea arabica samples ((X) over bar +/- SD:0.059 +/- 0.03, ranging from 0.016 to 0.095 g kg(-1)). (C) 1998 Elsevier Science Ltd. All rights reserved.