Development of analytical methods and data banks to control the authenticity of actives secondary metabolites from aromatic and medicinal plants ; Développement de méthodes analytiques et de banques de données pour le contrôle de l'authenticité de métabolites secondaires actifs issus de plantes aromatiques et médicinales

Natural raw materials are sometimes susceptible to be adulterated: essential oils sold to consumers do not always possess their original compositions, despite of being labeled 100% pure and natural. Suppliers resort to adulterate their products by adding low-cost products to their natural materials to improve the product quality, to increase the raw material volume, or for economic reasons. Thus, it is necessary to develop methods of authentication to identify such practices in order to empower consumers to be sure of the natural quality of their purchases and to enable suppliers to prove the authenticity of their products. Enantiomeric analyses, isotopic studies, and impurities researches are the three main axes of this thesis project and are applied to authenticate essential oils of wintergreen, allium species, neroli, spearmint, cinnamon, and cypriol. To ensure the authenticity of these natural products, it is critical to provide reference values useful to characterize adulteration. Therefore, in addition to analytical development, establishment of data banks based on authentic samples from various origins is also required. Accurate methods are needed to validate essential oil authenticity in commercial market rampant with fraudulent products. Companies must strictly regulate their supply chain to ensure authenticity, brand trust, and perceived value for the price. Novel methodologies were carried out, including compound specific isotope ratios δ18O and δ34S determination. Complex adulterations were highlighted, comprising 14C-labeled molecules and hemisynthesis origin products additions. ; Les matières naturelles aromatiques, telles que les huiles essentielles, que l’on retrouve sur le marché, ne sont pas toujours authentiques, bien que ces produits soient vendus comme étant 100% purs et naturels. Certains fournisseurs fraudent leurs produits afin de réduire les coûts de production, d’améliorer la qualité des huiles essentielles ou encore pour augmenter artificiellement les volumes de production. Les huiles ...