Optimization and mechanistic study for efficient extraction of curcuminoids from turmeric using a natural hydrophobic...

Curcuminoids, the principal bioactive constituents of turmeric, are in high demand across various industries. Developing efficient and green extraction techniques is therefore crucial. This study introduces a novel natural hydrophobic deep eutectic solvent (HDES) composed of anisyl alcohol and thymol for the ultrasound-assisted extraction of curcuminoids. The extraction process was optimized using single-factor experiments and response surface methodology. Under the optimized conditions, where the liquid-to-solid ratio is 18.64 mL/g, the extraction temperature is 22 °C, the ultrasonication time is 26.5 min, and the extraction time is 60 min, the single extraction obtained a high yield of 62.18 mg/g, significantly surpassing that obtained with conventional methanol. Furthermore, the HDES achieved a remarkable cumulative yield of 456.54 mg/g over multiple extraction cycles, highlighting its sustainability and superior solubility. Mechanistic investigations through molecular dynamics simulations revealed that the high extraction efficiency is primarily governed by van der Waals forces.