New analytical strategies for the characterization of bioactive compounds

Résumé

This PhD thesis has been carried out in the University of the Basque Country(UPV/EHU), together with the collaboration of IDOKI SFC S.L., the University ofStrasbourg, the University of Valladolid and the University of Copenhagen.Extraction methods of natural products by means of Supercritical Fluids andUltrasounds have been optimized employing design of experiments. In theseextractions two kinds of valuable compounds have been studied, volatile compoundsand antioxidants. The analyses of the volatile compounds extracts from aromatic plantshave been carried out in gas chromatography, mono and two-dimensional. The samemethodology was employed with citrus peels in order to extract and analyze thevolatiles and the antioxidants.After the experience reached with the analyses of volatiles, new techniques wereemployed in the characterization and quantification of coffee samples from differentorigins. The volatile compounds development was studied during the roasting process.Furthermore, the physic-chemical changes in the bean were examined by means ofnon-destructive techniques. In order to handle the data obtained with these techniques,advanced chemometrics were necessary. This data processing was also very useful forthe analysis of cannabis extracts obtained with SF due to their complexity. Thedeterpenation of this plant was efficiently accomplished and two valuable groups ofcompounds were obtained, volatile compounds (monoterpenes and sesquiterpenes) andcannabinoids. Due to the chemical similarity of the compounds, co-elutions wereappreciated and the resolution of the compounds in each peak was necessary.