Natural Deep Eutectic Solvents Combined with Supercritical Carbon Dioxide for the Extraction of Curcuminoids from Turmeric

Imagine extracting the golden power of turmeric with nothing but CO2 and natural plant-based solvents—this new method boosts curcuminoid yield by over 140 times compared to CO2 alone.

Turmeric's bioactive compounds, curcuminoids, are famous for their antioxidant, anti-inflammatory, and neuroprotective powers. But getting them out of the root efficiently and sustainably has been a challenge. Now, researchers have combined two green solvents—supercritical CO2 and natural deep eutectic solvents (NADESs)—into a single extraction process that dramatically boosts yield.

Using a Box-Behnken design, they optimized pressure, CO2 volume, and temperature. Then, they added a menthol-lactic acid NADES as a cosolvent at a 1:20 ratio of plant material to NADES. The result: a curcuminoid yield of 33.35 mg/g, far surpassing plain scCO2 (0.234 mg/g), ultrasound-assisted NADES (30.50 mg/g), and alcohol-based methods (22.95–26.42 mg/g).

The extract didn't just pack a punch in quantity—it also showed strong antioxidant activity and inhibited key enzymes like acetylcholinesterase and tyrosinase. Toxicity tests on aquatic organisms revealed a concentration-dependent response, with Daphnia pulex particularly sensitive, hinting at the need for careful use.

This one-pot green approach not only maximizes curcuminoid extraction but also preserves bioactivity, offering a sustainable path for nutraceutical and pharmaceutical applications.

Key Points

• scCO2–NADES extraction yields 33.35 mg/g curcuminoids, 140x more than scCO2 alone.
• Menthol-lactic acid NADES as cosolvent at 1:20 ratio boosts yield.
• Extract shows antioxidant activity and inhibits acetylcholinesterase, butyrylcholinesterase, and tyrosinase.