Advanced NADES-based extraction processes for the recovery of phenolic compounds from Hass avocado residues: A sustainable valorization strategy

What if avocado waste could become a treasure trove of health-boosting compounds? Scientists have found a green way to unlock it.

Avocado lovers, rejoice—your favorite fruit's leftovers are getting a second life. Researchers have turned to Natural Deep Eutectic Solvents (NADES), eco-friendly alternatives to traditional solvents, to extract phenolic compounds from Hass avocado peels and seeds. These compounds are known for their antioxidant power, and the team wanted to see how well NADES could recover them using advanced techniques like ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE).

They prepared ten different NADES mixtures, pairing choline chloride or betaine with donors like fructose, glucose, lactic acid, citric acid, or glycerol. The results were striking: the type of solvent and extraction method significantly influenced the total phenol content, proanthocyanidins, monomeric anthocyanins, and antioxidant capacity. In particular, PLE stood out, boosting the extraction from the epicarp (peel) to impressive levels—185 mg gallic acid equivalent per gram for phenols and 77.8 mg proanthocyanidin B2 per gram for proanthocyanidins.

Using high-resolution mass spectrometry, the researchers identified that mixtures like ChCl:Fru and ChCl:Lac were especially effective, especially when combined with PLE. This isn't just a lab curiosity—it's a sustainable strategy to turn agricultural waste into valuable extracts, reducing environmental impact while producing bioactive compounds. The study highlights that high-pressure extraction with NADES is a promising path toward greener, more efficient recovery of phenolics from avocado residues.

Key Points

• NADES with PLE boosts phenolic recovery from avocado peels and seeds.
• ChCl:Fru and ChCl:Lac show high extraction capacity.
• Sustainable valorization of Hass avocado by-products achieved.