Maximizing the neuroprotection from Citrus aurantium leaves: Optimization of a blended extract from a sequential extraction process with compressed fluids and NADES

What if the leaves left over from pruning bitter orange trees could become a weapon against neurodegenerative diseases? A new study turns this agricultural waste into a potent neuroprotective extract.

Citrus aurantium, the bitter orange, is rarely eaten fresh. Its real destiny is marmalade. But after the harvest, tons of leaves are discarded as waste. Now, scientists have found a way to give these leaves a second life—one that could protect the brain.

Using a three-step green extraction process, the team first applied supercritical fluid extraction (SFE), then pressurized liquid extraction (PLE) with natural deep eutectic solvents (NADES), and finally an antisolvent step. This is the first time PLE with NADES combined with an antisolvent re-extraction has been presented. They also developed novel protocols to remove NADES from the extract efficiently.

The resulting three fractions contain diverse bioactive compounds—carotenoids, terpenes, and phenolics—each with different properties. By optimizing the blend of these fractions, the researchers maximized the extract's preventive potential against neurodegenerative diseases. And when they scaled up the process to a semi-pilot level, the bioactive values got even better.

This research turns a pruning problem into a promising neuroprotective solution, proving that green chemistry and waste valorization can go hand in hand.

Key Points

• First PLE+NADES with antisolvent re-extraction
• Optimized blend boosts neuroprotective potential
• Semi-pilot scale increases bioactive values