Discrimination between arabica and robusta coffee species on the basis of their tocopherol profiles

The tocopherol profiles of arabica and robusta coffee beans, both green and roasted, were ascertained. A solid-liquid micro-extraction method was used, and the quantification performed by normal-phase HPLC/diode-array/fluorescence detection. Regarding green arabicas, the mean contents were 2.7 +/- 0.4 mg/100 g, for alpha-tocopherol, and 8.0 +/- 0.9 mg/100 g. for beta-tocopherol. For green robustas, mean Values of 1.7 +/- 0.3 and 2.1 +/- 0.3 mg/100 g were found for alpha- and beta-tocopherol, respectively. Generally. more than 90% of tocopherols remained after the roasting procedure, except for beta-tocopherol in robustas, whose mean degradation was approximately 25% when expressed as dry weight. No gamma-tocopherol was detected in any sample. Tile results show that tocopherol profile could be useful in the discrimination of arabica and robusta coffees (either green or roasted). (C) 2008 Elsevier Ltd. All rights reserved.