Extraction and purification of curcuminoids from Curcuma longa using microwave assisted deep eutectic solvent based system and cost estimation

Abstract

Deep eutectic solvents (DESs) are explored to develop sustainable and green processes as an alternative to conventional solvents. Likewise, microwave-assisted extraction (MAE) is a widely studied eco-friendly method owing to enhanced extraction of biomolecules with lower solvent and time requirement. The present work illustrated the combined effect of DES as a green medium under microwave irradiation to enhance curcuminoids extraction from turmeric. Choline chloride-alcohol, -acid, and -amide DESs were screened under the microwave, and choline chloride-citric acid (ChCl-CA) DES was stable and resulted in maximum extraction at a 1:1 molar ratio. The ChCl-CA DES yielded 89.87 mg/g curcuminoids with 30% water addition, 1:20 (g/mL) solid to DES ratio, and 0.150 > 0.212 µm particle size under 60 W microwave power and “HIGH stirring” mode in 8 min soaking time and 6 min of irradiation time. Moreover, 43 ± 1.78% curcuminoids were recovered from MA-DES extract by anti-solvent precipitation process comprising 82.32% purity. In addition, the MA-DES method drastically reduced the solvent requirement and extraction time, thereby minimizing energy consumption and cost compared to conventional extraction processes. FT-IR data confirmed the hydrogen bonding formation in DES. The optimized MA-DES extraction process can be implemented as a green and effective alternative to traditional methods for extracting bioactive compounds.