Pulsed electric fields-assisted extraction of valuable compounds from red grape pomace: Process optimization using response surface methodology

What if the leftover skins and seeds from winemaking could become a goldmine of health-boosting compounds? A new study shows how a gentle electric pulse can unlock them.

Every year, winemaking leaves behind mountains of grape pomace—the skins, seeds, and stems that most people throw away. But this byproduct is packed with bioactive compounds like phenolics and anthocyanins, which have antioxidant and anti-inflammatory potential. The challenge? Extracting them efficiently without damaging their delicate structure.

Enter pulsed electric fields (PEF). This mild, scalable technology uses short electrical pulses to create tiny pores in plant cell membranes, making it easier to release valuable compounds. In this study, researchers optimized PEF-assisted extraction from red grape pomace using response surface methodology. They varied the electric field strength (0.5–5 kV/cm) and energy input (1–20 kJ/kg), measuring the cell disintegration index to find the sweet spot.

After PEF treatment, they performed solid-liquid extraction under different temperatures (20–50°C), times (30–300 minutes), and ethanol concentrations (0–50%). They then measured total phenolics, flavonoids, anthocyanins, tannins, and antioxidant activity. The results showed that PEF significantly boosted extraction yields compared to untreated tissue, and the phenolic composition was confirmed via HPLC-PDA.

This isn't just about saving waste—it's about turning a problem into a resource. With optimized PEF, the wine industry could produce high-value extracts for food, cosmetics, and pharmaceuticals, all while reducing environmental impact.

Key Points

• PEF boosts extraction of bioactive compounds from grape pomace.
• Optimization via response surface methodology improves yields.
• Phenolic composition confirmed by HPLC-PDA analysis.