INFLUENCE OF THE BAKING PROCESS ON CANNABINOID CONTENTS AND PROFILES IN HEMP-CONTAINING BREAD AND SURVEY OF MARKET SAMPLES

Since 2023, Commission Regulation (EU) 2023/915 has regulated Δ9-THC equivalents (Δ9-THC + 0.877×THCA) with maximum levels in hemp seeds and processed hemp seed products. Δ9-THC (tetrahydrocannabinol) is the most relevant psychoactive cannabinoid in the hemp plant. Cannabinoid acids can be converted to neutral cannabinoids by thermal decarboxylation. This is particularly relevant in the case of THCA (tetrahydrocannabinolic acid), where the psychoactive Δ9-THC can be formed. Hemp breads are becoming increasingly popular. The aim of this study was to quantify cannabinoid contents and profiles of hemp-containing breads. It is the first systematic description of the influence of the baking process on cannabinoid contents and profiles. Hemp seed breads were manufactured at small-business scale and analysed using a validated HPLC-MS/MS method. Rye-wheat breads containing 10% unhulled hemp seeds (based on total flour weight) were baked at 180-260 °C for 40-60 min. The breads were separated into crust, crumb, whole slices, and the initial raw dough sample was retained (84 samples in total). In addition, 26 bakery products containing hemp were purchased and analysed. Baking under different conditions revealed a dependence of acidic cannabinoid decarboxylation on temperature and time. Compared to the acid/neutral ratio (A/N) in the raw dough (A/N 4.0), the ratio decreased to A/N 2.0 in the 180 °C/40 min bread and to A/N 0.9 in the 260 °C/60 min bread. At the same time, the Δ9-THC content increased by up to 48% (260 °C/60 min bread) compared to the raw dough, further emphasising the importance of decarboxylation. Decarboxylation and Δ9-THC formation were more pronounced in the crust. Comparing raw dough and the 260°C/60 min bread, in the crust A/N decreased from 4.0 to 0.4 and Δ9-THC increased by 105%. In the corresponding crumb, A/N decreased to 1.2 and Δ9-THC increased by 43%. The difference is explained by the different thermal profiles in the two compartments, highlighting the effects of baking parameters on cannabinoid contents and profiles in bakery products. The total cannabinoid content in the market samples (n = 26) ranged from 68 to 4,603 μg/kg and the Δ9-THC equivalents were up to 66 μg/kg. The sample with the highest Δ9-THC equivalents was a gingerbread covered with dehulled hemp seeds. The highest total cannabinoid content was found in a wholemeal rye bread, which is the most common baked product containing hemp found during sample collection.