Fabrication of curcumin-loaded oleogels using camellia oil bodies and gum arabic/chitosan coatings for controlled release applications

This study has explored the potential of plant-derived oil bodies (OBs)-based oleogels as novel drug delivery systems for in vitro release under simulated physiological conditions. To obtain stable OBs-based oleogels, gum arabic (GA) and chitosan (CH) were coated onto the curcumin-loaded OBs using an electrostatic deposition technique, followed by 2,3,4-trihydroxybenzaldehyde (TB) induced Schiff-base cross-linking. Microstructural analyses indicated successful encapsulation of curcumin into the hydrophobic domain of the OBs through a pH-driven method combined with ultrasound treatment. The curcumin encapsulation efficiency of OBs increased up to 83.65 % and 92.18 % when GA and GA-CH coatings were applied, respectively, compared to uncoated OBs (63.47 %). In addition, GA-CH coatings retained the structural integrity of oleogel droplets with superior oil-holding capacity (99.07 %), while TB addition induced interconnected 3D-network structures with excellent gel strength (≥4.8 × 105 Pa) and thermal stability (≥80 °C). GA-CH coated oleogels appeared to provide the best protection for loaded bioactive against UV irradiation and high temperature-induced degradation during long-term storage. The combination of biopolymer coatings and TB-induced Schiff-base cross-linking synergistically hindered the simulated gastric degradability of oleogels, releasing only 23.35 %, 12.46 % and 7.19 % of curcumin by GA, GA-CH and GA-CH-TB stabilized oleogels, respectively, while also resulting in sustained release effects during intestinal conditions.