High voltage electrical discharge-assisted extraction of bioactive compounds from red onion peel (Allium cepa L.) using natural deep eutectic solvents: Efficiency, stability, and functional properties

A kitchen waste item just got a stunning upgrade: red onion peels, usually thrown away, can now be zapped with electricity and soaked in green solvents to unlock their hidden treasure trove of health-boosting compounds. This isn't just recycling—it's a high-voltage makeover for food science.

Forget harsh chemicals. Scientists have paired a physical jolt—high voltage electrical discharge (HVED)—with nature's own solvents, called NADES, to pull bioactive compounds from red onion peels. The method is a one-two punch: first, the peels are pretreated with electricity at 120 V across 20 pulses; then, a selected green solvent, citric acid:glycerol, does the extraction work at a gentle 40°C for an hour.

Key Points

• HVED + NADES extracts 1.8× more flavonoids than ethanol.
• Citric acid:glycerol boosts antioxidant activity by 20%.
• Green method slows anthocyanin degradation, extending shelf life.