Novel high internal phase emulsion gels stabilized solely by hemp protein isolate: Enhancement of cannabidiol chemical stability and bioaccessibility

This study aims to fabricate high internal phase emulsion gels (HIPEGs) using modified hemp protein isolates for microencapsulating cannabidiol (CBD) to enhance their chemical stability and bioaccessibility. Importantly, the combined effect of CBD concentrations (0.1 vs 0.5 wt%) and post gel storage conditions (before-refrigeration (BR) vs after-refrigeration (AR)) on the properties of HIPEGs were investigated. The results showed that the CBD concentration above 0.4 % is necessary to fabricate a stable HIPEG. The rheological properties of HIPEGs were influenced by CBD concentration and refrigeration. The AR gels with 0.5 % CBD showed the highest gel strength (up to 91.7 Pa) and solid-like structures. These properties allowed to HIPEGs maintain good physical stability during storage at 4, 25, and 37 degrees C for 14 days due to the interconnected polyhedral protein matrices and thick interfacial protein layers. These unique protein architectures offered superior protection against CBD degradation (<2 % of initial added amount) for 100 days during exposure to light and temperature (25 or 37 degrees C). The INFOGEST digestion results showed the BR gels effectively protected CBD during digestion and consequently improved their stability and bioaccessibility up to 95 % and 74 %, respectively. Overall, the fabricated HIPEGs could be valuable for nutraceutical delivery.