New horizons for the enhanced recovery of phenolic compounds by integration of natural deep eutectic solvents and microwave-assisted extraction

What if the humble date seed, often discarded as waste, could become a treasure trove of health-boosting compounds? A new study shows how microwave-assisted extraction with natural deep eutectic solvents unlocks this potential.

Date seeds, the often-overlooked byproduct of the date fruit industry, are packed with nutrients and bioactive compounds. Researchers have now optimized a microwave-assisted extraction (MAE) method to efficiently pull out these valuable phenolic compounds from defatted date seed powder (DSP). The process uses natural deep eutectic solvents, a green alternative to traditional solvents, making the extraction more sustainable.

Under optimal conditions—700 W power, 6 minutes, 45°C, and particle size under 125 micrometers—the team achieved impressive yields. The total phenolic content reached 15.88 mg GAE/g DSP, while total flavonoid content was 8.51 mg QE/g DSP. Antioxidant activities were also notable, with ABTS, DPPH, and FRAP values of 17.93, 61.68, and 39.74 mmol TE/g DSP, respectively.

The study also revealed that the three date varieties (Khalas, Fardh, and Khenaizi) differed significantly in their bioactive profiles. Key phenolic compounds identified included benzoic acid, catechin, ferulic acid, caffeic acid, and vanillin. Even the leftover residues after extraction retained useful properties, and when both extracts and residues were incorporated into biscuits, they boosted the snacks' phenolic and antioxidant content.

This research highlights a win-win scenario: reducing agricultural waste while creating functional foods with enhanced health benefits. It's a step toward more sustainable food production, turning a simple seed into a valuable ingredient.

Key Points

• Optimized MAE with NADES for date seed phenolics.
• High antioxidant yields under green, mild conditions.
• Date seed extracts and residues boost biscuit bioactivity.