Supercritical Carbon Dioxide (scCO2) Extraction of Phenolic Compounds from Lavender (Lavandula angustifolia) Flowers: A Box-Behnken experimental optimization

What if the secret to unlocking lavender's health-boosting phenolics lies not in water or alcohol, but in a gas turned liquid? Supercritical CO2 just proved it—extracting up to 9.2% yield with no toxic leftovers.

Phenolic compounds—nature's tiny defenders—are linked to everything from antioxidant power to disease protection. But scientists have long struggled to find a single, clean way to pull them from plants. Enter supercritical carbon dioxide: a green method that leaves no organic solvent residues behind, just pure extract.

A team took lavender flowers and subjected them to scCO2 under varying pressure, temperature, and time. Using a Box-Behnken statistical design, they mapped extraction yields and total phenolic content across 200–300 bar, 40–60°C, and 15–45 minutes. The results? Yields ranged from 4.3 to 9.2 wt.%, with the peak at 60°C, 250 bar, and 45 minutes—also hitting the highest phenolic content of 10.17 mg GAE/g extract.

But the optimization didn't stop there. The model predicted even better conditions: 54.5°C, 297.9 bar, and 45 minutes to maximize phenolics. And as pressure rose, so did antioxidant scavenging activity—a clear sign that greener extraction can also be smarter. This isn't just about lavender; it's a blueprint for clean, efficient phytochemical recovery.

Key Points

• scCO2 yields 4.3–9.2 wt.% from lavender flowers.
• Optimal phenolics at 54.5°C, 297.9 bar, 45 min.
• Higher pressure boosts antioxidant scavenging activity.