Entwicklung und Anwendung von HPLC-MS/MS Methoden zur Quantifizierung von Cannabinoidgehalten und -profilen in hanfhaltigen Produkten und zur Untersuchung des Einflusses thermischer Prozessierungen auf Cannabinoidgehalte und -profile in hanfhaltigen Lebensmitteln

Components of industrial hemp (Cannabis sativa L.), such as hemp seeds or hemp seed oil, can be placed on the market in the EU as foodstuffs. Hemp seeds are characterised by a nutritionally valuable fatty acid spectrum. In addition, foods containing hemp and unauthorised products containing cannabidiol (CBD) (e.g., CBD oils) are established as lifestyle products. Products containing hemp naturally contain cannabinoids, including the psychoactive Δ9-tetrahydrocannabinol (Δ 9-THC) and its precursor tetrahydrocannabinolic acid (THCA), which is converted into Δ9-THC by thermal decarboxylation. Due to potential health risks, the European Food Safety Authority (EFSA) has derived an Acute Reference Dose (ARfD) for Δ 9-THC. In addition, maximum levels for Δ9-THC equivalents have been regulated throughout the EU. For CBD, toxicological effects such as liver damage are discussed at high intake levels. Scientific data on cannabinoid content in foods containing hemp is limited to date. There is often a lack of validated quantitative methods that can differentiate between acidic (tending to be non-bioactive) and neutral (tending to be bioactive) cannabinoids – an essential aspect for risk assessment. In addition, little is known about the influence of typical food-specific thermal processing on cannabinoid contents and profiles. The aim of this dissertation was to extend the analytical basis for exposure and risk assessment of hemp containing foods. Three hypotheses were pursued, which were to be tested after preparatory analytical method development: (1) Market samples show cannabinoid contents and profiles relevant for risk assessment. (2) Thermal processing has significant effects on cannabinoid contents and profiles. (3) The results on content data and effects of thermal processing support an improved risk assessment. Methodologically, an HPLC-MS/MS method was developed which, in contrast to previously used methods such as GC-FID or GC-MS, does not require derivatisation and enables the differentiation of acidic and neutral cannabinoids as well as specific and sensitive quantification. In the first study, the method was used to analyse 30 commercially available hemp seed edible oils. In addition, a representative oil was heated under different conditions (temperature/time). The results showed a temperature-dependent increase in Δ9-THC with a simultaneous decrease in Δ9-THC equivalents. In addition, balancing gaps were identified that indicate the formation of previously unknown transformation products. In the second study, the method for detecting Δ 8-THC, 9(R)-HHC and 9(S)-HHC in CBD oils was extended. Although these can also occur naturally in trace amounts, they are of particular importance due to their semi-synthetic origin. The method was adapted so that it can quantify very high CBD contents (% range) as well as traces of other cannabinoids (ppm range) within a measurement sequence. The results show that many products contain toxicologically relevant levels of Δ9-THC, which means that a potential exceedance of the ARfD cannot be ruled out at normal consumption levels. The third study deals with the development and validation of a method for the determination of cannabinoids in baked goods containing hemp. Both market samples and bread baked under systematically varying conditions with a defined hemp seed content were analysed. The results demonstrate the decarboxylation of acidic cannabinoids as a function of baking time and temperature. In addition, differences in the thermally-induced effects between crust and crumb were identified. Overall, the measured levels were below toxicological and regulatory guideline values. The results of the thermal processing indicate potential transformation reactions that have not yet been fully analysed. This work provides significant contributions to the differentiated analytical quantification, evaluation and regulation of cannabinoids in hemp-containing foods.