Green Extraction of Antioxidant-Rich Flavonoids from Fagonia cretica Using Deep Eutectic Solvents

What if the secret to greener, more powerful antioxidant extraction was hiding in a simple mix of betaine and acetic acid? This study found a way to boost flavonoid yield from a desert plant while being kind to the planet.

Deep eutectic solvents (DESs) are emerging as the eco-friendly superheroes of chemical extraction. In this study, scientists optimized the extraction of flavonoids from Fagonia cretica, a hardy desert plant, using six different DESs. The star performer was a betaine–acetic acid combo, thanks to its remarkably low viscosity of just 4.98 mPa·s, which allows it to penetrate plant tissues more effectively.

The team fine-tuned the process: a 1:4 molar ratio of betaine to acetic acid, 25% water, a solid/liquid ratio of 1:60 g/mL, and a gentle 50°C for 30 minutes. Under these conditions, flavonoid yield was maximized without sacrificing bioactivity. When tested, these DES-extracted flavonoids showed superior scavenging power against DPPH and hydroxyl radicals compared to those extracted with ethanol, suggesting that DESs can actually enhance antioxidant properties.

But the green story doesn't end there. The DESs could be recycled using ultracapacitor porous activated carbon, achieving an impressive 89.78% recovery. Even after six cycles, the reused DES maintained 92% extraction efficiency, proving that this approach is both sustainable and cost-effective. This study positions DES-based extraction as a powerful, environmentally friendly tool for isolating bioactive compounds, offering a win-win for green chemistry and high-quality antioxidant production.

Key Points

• Betaine–acetic acid DES yields highest flavonoid extraction.
• Optimal: 1:4 molar ratio, 25% water, 50°C, 30 min.
• DES recyclable: 89.78% recovery, 92% efficiency after 6 cycles.