Natural deep eutectic solvents as a green extraction of polyphenols from spent coffee ground with enhanced bioactivities

What if your morning cup of coffee could help create powerful, eco-friendly ingredients without relying on toxic, flammable chemicals? Researchers are turning everyday waste into a scientific triumph using designer green liquids.

Conventional extraction methods often rely on highly pollutant and flammable organic solvents. To combat this, science is turning toward Natural Deep Eutectic Solvents, or NADES. These green, non-toxic mixtures form when components like sugars, polyols, choline chloride, or betaine interact through hydrogen bonding, resulting in a melting point much lower than their individual parts.

Researchers recently put two specific NADES systems—betaine:triethylene glycol and choline chloride:1,2-propanediol—to the test. Their mission? To extract valuable polyphenols from spent coffee grounds, a common by-product of coffee processing.

The results were striking. NADES proved just as effective at extracting polyphenols as conventional green methods like hot water and hydroalcoholic solutions, but with a major bonus: they operated at milder temperatures without flammable solvents. Even better, the antimicrobial activity of the NADES extracts rocketed to 10 times higher than that of traditional ethanolic and aqueous extracts. Because of their low toxicity, these natural solvents show immense promise as formulation aids for food ingredients and nutraceuticals.

Key Points

• NADES offer a green alternative to pollutant solvents
• Extracted polyphenols from spent coffee ground successfully
• Antimicrobial activity was 10 times higher