Single-step production of ready-to-use cannabidiol oils via supercritical CO2 co-extraction of hemp flowers and seeds

Hemp ( Cannabis sativa L.) flowers are the primary source for a wide range of cannabidiol (CBD)-based formulations, particularly CBD oils. Traditional production methods typically involve two separate steps: extracting active compounds and incorporating them into a carrier oil. Although supercritical CO 2 (scCO 2 ) extraction has been applied individually to hemp flowers and oily seeds, a single-step co-extraction approach has not been previously explored. This study investigates the feasibility of scCO 2 co-extraction of hemp flowers with oily seeds to produce CBD oils with tunable cannabinoid concentrations. Three seed types (i.e., hemp, sesame, and sunflower) were screened, and key process parameters were systematically varied, including flower-to-seed ratios, pressure, temperature, and CO 2 flow rate. Suitable conditions were determined to be a flower-to-seed ratio of 1:3, a pressure of 300 bar, a temperature of 40 °C, and a CO 2 flow rate of 12.6 g/min. With the proposed approach, CBD oils containing up to 10 wt% CBD and a complex nutritional profile, including essential fatty acids and minor bioactives such as tocopherols, carotenoids, and chlorophylls, could be obtained. Importantly, cannabinoid concentration could be adjusted by varying the flower-to-seed ratio. This proof-of-concept process demonstrates that scCO 2 co-extraction offers a sustainable alternative for producing high-quality CBD-rich oils, with potential for industrial applications. • First demonstration of scCO 2 co-extraction of hemp flowers with oily seeds to produce CBD oils. • Suitable parameters (i.e., pressure, temperature, flower-to-seed ratio, and CO 2 flow rate) were identified. • Cannabinoid levels in the oils can be fine-tuned by changing the flower-to-seed ratio. • The approach represents a sustainable way for the single-step production CBD oils.