The Value of Using Green Extraction Techniques to Enhance Polyphenol Content and Antioxidant Activity in Nasturtium officinale Leaves

What if the key to a super-antioxidant extract lies not in exotic plants, but in a humble watercress leaf—and the secret is a cocktail of green technologies?

Watercress, or Nasturtium officinale, is often overlooked as just a salad green. But new research reveals it as a powerhouse of bioactive compounds—if you know how to extract them. Scientists optimized the extraction process using response surface methodology, tweaking temperature, time, and solvent composition. They compared conventional stirring with two green techniques: pulsed electric fields and ultrasound, both alone and in combination.

The winning formula? A triple threat: PEF, ultrasound, and stirring, with a 50% ethanol solvent, heated to 80°C for 30 minutes. Under these conditions, the leaf extract boasted impressive numbers: rosmarinic acid at 3.42 mg per gram of dried weight, chlorogenic acid at 3.13 mg/g, and a total polyphenol content of 28.82 mg gallic acid equivalents per gram. The antioxidant power was equally striking, with FRAP assays showing 57.15 µmol AAE/g and DPPH scavenging at 47.55 µmol AAE/g.

This isn't just lab trivia. The optimized extract opens doors for the food, cosmetic, and pharmaceutical industries, offering a natural, value-added product. The study underscores that green extraction isn't just eco-friendly—it's also effective, proving that sustainability and potency can go hand in hand.

Key Points

• Optimized extraction boosts polyphenols in watercress leaves.
• Green combo: PEF, ultrasound, and stirring at 80°C.
• Extract shows strong antioxidant activity, ideal for industry.