Potential of microalgae biomass as carotenoids source using natural deep eutectic solvents

Tiny green algae may hold the key to a greener way of extracting vital nutrients—using solvents made from fatty acids. But can these natural mixtures outperform traditional chemicals?

Microalgae like Chlorella vulgaris are packed with carotenoids—powerful antioxidants that give plants their vibrant colors. But extracting them often requires harsh, toxic solvents. Now, scientists are turning to a novel class of solvents called Natural Hydrophobic Deep Eutectic Solvents (NaHDESs), made entirely from fatty acids. These solvents are not only eco-friendly but also highly effective. In a recent study, researchers screened seven low-viscosity NaHDESs, each composed of fatty acids acting as both hydrogen bond donors and acceptors. Among them, a mixture of nonanoic and dodecanoic acid (3:1) stood out as the most promising. Using a Box-Behnken design, they optimized the solvent ratio, sample ratio, and extraction time to maximize carotenoid recovery. The results were impressive: under optimal conditions, they recovered 2.00 mg/mL of total carotenoids, including lutein, zeaxanthin, and β-carotene. The extract also showed strong antioxidant activity, with a 9.13% inhibition per mL. Notably, this NaHDES outperformed acetone, a common but toxic solvent. This breakthrough suggests that NaHDESs could be a sustainable alternative for extracting bioactive compounds from microalgae, paving the way for greener food and supplement production.

Key Points

• Chlorella vulgaris carotenoids extracted with NaHDESs
• Nonanoic/dodecanoic acid (3:1) most effective NaHDES
• NaHDES outperformed acetone in antioxidant activity