Utilization of accelerated solvent extraction and deep eutectic solvents as synergistic green extraction technique for the recovery of bioactive compounds from date palm (Phoenix dactylifera L.) seeds

Date seeds, the often-discarded byproduct of a beloved fruit, hide a treasure trove of bioactive compounds—and scientists have found a greener way to unlock them.

Every date fruit leaves behind a seed. Most end up as waste, but a new study turns these humble seeds into a source of valuable compounds using an eco-friendly extraction duo. The team paired accelerated solvent extraction (ASE)—an automated, efficient technique—with deep eutectic solvents (DES), a class of green solvents that are cheap and biodegradable.

Six different DES were tested, and the winner was a combination of lactic acid and ethylene glycol. The researchers then fine-tuned the process by varying the solid-to-solvent ratio, static cycles, time, temperature, and particle size. The optimal conditions were a ratio of 2.0:2:50 g/g/mL, two static cycles, and a 10-minute static time at 100°C.

When compared to other green methods—microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE)—MAE came out on top for recovering date seed bioactive compounds, followed by ASE and UAE. The study also revealed a key insight: for DES to work well in an ASE system, it must have low viscosity to move freely through the extraction cell.

This work shows how agro-waste like date seeds can be transformed into value-added products, offering a sustainable path forward for the food and pharmaceutical industries.

Key Points

• DES (lactic acid: ethylene glycol) was the most efficient solvent.
• Optimal conditions: 2.0:2:50 g/g/mL, 2 cycles, 10 min, 100°C.
• MAE outperformed ASE and UAE for bioactive recovery.