Microwave-assisted extraction (MAE) of bioactive compounds from blueberry by-products using a sugar-based NADES: A novelty in green chemistry

What if the secret to greener chemistry lies in sugar, glycerol, and lactic acid—ingredients found in your kitchen? A new study turns blueberry waste into a treasure trove of antioxidants using a sweet, eco-friendly solvent.

Blueberry juice production leaves behind 20–30% of the fruit as waste—a costly problem with a hidden opportunity. Scientists at the University of Turin saw not trash, but a treasure chest of anthocyanins, the pigments behind the berry's deep blue hue. Their mission: extract these bioactive compounds without harsh, toxic solvents. The answer? A novel trio of glucose, glycerol, and lactic acid, mixed in a precise 1:2:5 ratio to form a Natural Deep Eutectic Solvent (NADES). This sugar-based solvent is not only biodegradable but also safe for food and cosmetic applications. To maximize efficiency, the team used a Design of Experiments approach, testing four key parameters: extraction heat, time, ramp-to-isotherm ratio, and solvent-to-matrix ratio. After fine-tuning with a D-optimal model and rigorous statistical validation, they locked in the sweet spot: 60°C for 30 minutes, with a 2 min/min ramp and 20 mL/g solvent ratio. The results were striking—this green solvent outperformed both a choline chloride-based NADES and a traditional methanol-HCl mixture. It's a win for the planet and a step toward a circular economy where waste becomes wealth.

Key Points

• Sugar-based NADES outperforms conventional solvents
• Optimized MAE: 60°C, 30 min, 20 mL/g
• Blueberry waste yields anthocyanins sustainably