ANTIOXIDANT AND ANTIMICROBIAL POTENTIAL OF BLACKBERRY POLYPHENOLIC EXTRACTS: INFLUENCE OF DIFFERENT EXTRACTION TECHNIQUES AND SOLVENTS

Blackberries are more than just a tasty treat—they might be nature's own preservative, thanks to their polyphenols. But the way we extract these compounds can make or break their power.

Blackberries are packed with polyphenols, natural compounds known for their antioxidant and antimicrobial prowess. This study set out to find the best way to unlock these benefits, comparing different solvents and extraction techniques. The researchers tested ethanol and two natural deep eutectic solvents (NADES)—a choline chloride:glycerol mix and a choline chloride:lactic acid mix—using maceration, ultrasound, and microwave-assisted extraction. The results were telling: the acidic NADES (N2) outperformed both ethanol and the other NADES in extracting bioactives, while microwave assistance had the strongest impact on polyphenol content and color. All extracts showed significantly better antimicrobial activity than the ethanolic one, especially against Gram-positive bacteria. These findings hint that acidic NADES could be a game-changer for food preservation, though further optimization and real-world application studies are needed before blackberry extracts hit the mainstream.

Key Points

• Acidic NADES (N2) beats ethanol and other NADES for bioactives.
• Microwave extraction boosts polyphenol content and color.
• All extracts show stronger antimicrobial activity than ethanol, especially against Gram-positive bacteria.