Fabrication of natural deep eutectic solvent based water-in-oil high internal phase emulsion: Improving loading capacity and stability of curcumin

Water-in-oil high internal phase emulsions (HIPEW/O) are promising as fat substitutes and nutrient carriers in food systems. A method was developed to replace the water phase of HIPEW/O with natural deep eutectic solvents (NDES) to enhance the loading and stability of nutraceuticals. NDESs, comprising varying ratios of d-glucose, sucrose, and water, were used. Higher sucrose ratios resulted in larger crystals in NDES-based HIPEW/O. Glucose-to-sucrose molar ratios below 1 generated gel-like HIPEs with excellent thermal, centrifugal, freeze-thaw, and storage stability. Increased sucrose proportion in NDES promoted crystal formation, thus improving emulsion stability. NDES-HIPEs demonstrated high curcumin loading with high encapsulation efficiency. Crystal-containing NDES-HIPEs exhibited improved ultraviolet and gastrointestinal stability. This study presents a novel method for HIPEW/O preparation. Using NDES as the internal phase regulates crystal morphology, enhances emulsion stability, and protects nutrients. These unique emulsions hold potential as carriers for bioactive components in food, nutraceutical, and pharmaceutical applications.