HPLC analysis of tocopherols and triglycerides in coffee and their use as authentication parameters

The triglyceride and tocopherol contents of green and roasted coffee beans belonging to the arabica and robusta varieties were determined by reversed phase and normal phase high resolution liquid chromatography, respectively. Refractive index detector was used in the case of the triglycerides and fluorescence for tocopherols. Coffee oil was Soxhlet extracted with hexane. By considering the triglyceride and tocopherol profiles as chemical descriptors, a chemometric study with authentication purposes was performed to differentiate coffee varieties. Pattern recognition techniques like principal component analysis and linear discriminant analysis were carried out. Discrimination between arabica and robusta coffees was achieved with both profiles, but only tocopherols also allow the differentiation between green and roasted coffees.