Development of a Method Based on Natural Deep Eutectic Solvents for Extraction of Flavonoids from Food Samples

What if the secret to extracting valuable compounds from our food lies not in harsh chemicals, but in tailored green solvents inspired by nature itself?

Natural deep eutectic solvents are shaking up the world of natural product extraction as eco-friendly alternatives. In a groundbreaking approach, researchers have developed the first sample preparation method using these solvents specifically to extract eight key flavonoids—including rutin, quercetin, and naringenin—from a variety of everyday fruits, vegetables, and spices.

To find the ultimate recipe, the team tested 17 custom-tailored solvent types built from ingredients like choline chloride, betaine, and carnitine, alongside variables such as water content and liquid-to-solid ratios. Using response surface methodology to fine-tune the parameters, they unlocked a winning formula: a 30% water solution of acetylcholine chloride and lactic acid at a 2:1 ratio.

Operating at 60 °C with a 3:1 liquid-to-solid ratio, 30 minutes of extraction time, and a 1400 rpm stirring speed, this solid-liquid extraction method achieved an impressive flavonoid recovery rate of over 70%. The resulting extracts were then successfully analyzed using UHPLC with UV and MS/MS detection across diverse foods ranging from cranberries and onions to rosemary and black pepper.

Key Points

• First NADES method for extracting eight flavonoids from food
• Evaluated 17 tailored NADES compositions using multivariate optimization
• Achieved over 70% flavonoid recovery under optimized conditions