Greener extraction of anthocyanins and antioxidant activity from blackberry (Rubus spp) using natural deep eutectic solvents

What if the secret to capturing nature's most powerful antioxidants lay not in harsh chemicals, but in smart, designer green liquids? Researchers are unlocking the vibrant health compounds hidden inside blackberries using an innovative, eco-friendly solvent approach.

When scientists set out to extract valuable compounds from blackberries, they looked beyond traditional water, methanol, and ethanol. Instead, they synthesized sixteen different Natural Deep Eutectic Solvents (NADESs) crafted from combinations of choline chloride, sugars, organic acids, and polyalcohols. Testing their physical properties revealed that factors like viscosity, pH, and conductivity heavily depend on how these hydrogen bond donors and acceptors pair up.

The results speak for themselves. The top-performing NADES formulations triumphed in recovery metrics, yielding impressive levels of total phenolics, flavonoids, and anthocyanins. They also delivered exceptional antiradical activity, reducing power, and metal chelating capabilities.

Crucially, chemistry showed a clear preference: the more acidic NADES variants proved to be the most prominent champions for pulling out specific, targeted anthocyanins like cyanidin-3-glucoside, cyanidin-3-rutinoside, cyanidin chloride, and pelargonidin-3-glucoside. This green extraction strategy reliably targets vital plant phytochemicals, paving a brilliant path forward for future botanical research.

Key Points

• Sixteen distinct NADES synthesized and evaluated
• Acidic NADES maximized targeted anthocyanin extraction
• Outperformed conventional solvents in antioxidant recovery