Deep Eutectic Solvents (DESs) as Alternative Sustainable Media for the Extraction and Characterization of Bioactive Compounds from Winemaking Industry Wastes

What if the waste from your favorite glass of wine could become a treasure trove of health-boosting compounds? New research turns grape pomace into a goldmine using green chemistry.

Every year, the winemaking industry produces mountains of grape pomace—the skins, seeds, and stems left after pressing. This byproduct is often discarded, adding to the growing problem of agro-industrial waste. But hidden inside are bioactive molecules that could benefit human health, if only we could extract them sustainably.

In this study, scientists turned to natural deep eutectic solvents (DESs)—a green alternative to traditional organic solvents. They tested seven DESs on pomace from two grape varieties, Petit Verdot and Cabernet Sauvignon. Using HPLC-DAD, they identified and measured eight out of fifteen phenolic compounds, including three quercetin glucosides, known for their antioxidant power.

The most promising extracts came from a choline chloride/urea mixture with 40% water, which showed strong antioxidant activity in the DPPH assay. Meanwhile, a betaine/lactic acid blend with 40% water displayed notable antibacterial effects. These results suggest that DESs can unlock the value in wine waste, paving the way for polyphenol-enriched food and feed supplements in the future.

Key Points

• Green DESs extract bioactive compounds from grape pomace.
• Choline chloride/urea shows top antioxidant activity.
• Betaine/lactic acid blend offers antibacterial effects.