Development and Optimization of Green Extraction Process of Greek Mountain Tea (Sideritis scardica)

What if the secret to a greener, more powerful extraction lies in a humble mix of natural compounds? Greek mountain tea's bioactive riches just met their match in a betaine-based solvent.

Medicinal plants are treasure troves of bioactive compounds, and Greek mountain tea (Sideritis scardica) is no exception—packed with phytochemicals linked to various health benefits. But traditional extraction methods often rely on harsh, polluting solvents. Enter Natural Deep Eutectic Solvents (NADESs): sustainable, tailor-made liquids that could revolutionize how we harvest these valuable molecules.

In this study, scientists crafted six task-specific NADESs and tested their extraction power against the tea's total phenolic and flavonoid content. The standout? A betaine and 1,3-propanediol mixture, which they optimized using a Box–Behnken design, tweaking parameters like solid-to-liquid ratio, time, and water content.

The winning conditions—20 mg/g solid-to-liquid, 240 minutes, and 40% water as co-solvent—yielded impressive results: 49.2 mg GAE/g of phenolics and 45.9 mg CAE/g of flavonoids. That's roughly double what a conventional hydroethanolic extract achieved under the same setup (26.6 and 19.9 mg/g, respectively). Further analysis via HPLC-DAD revealed a distinct phytochemical profile, highlighting how the choice of solvent shapes what we extract. This green approach isn't just eco-friendly—it's smarter chemistry.

Key Points

• NADESs beat conventional solvents for extracting Greek mountain tea compounds.
• Optimized betaine/1,3-propanediol system doubled phenolic and flavonoid yields.
• Green extraction: 20 mg/g, 240 min, 40% water, eco-friendly and efficient.