Valorization of Agro-Industrial Byproducts for Green Extraction of Anthocyanins Using NADES

What if the secret to natural, sustainable food color was hiding in corn cobs and grape skins? A new study shows how eco-friendly solvents can unlock it.

The demand for clean-label products is pushing the food and cosmetic industries to ditch synthetic colorants. Anthocyanins, the pigments behind vibrant reds and purples, offer a natural alternative with added bioactive benefits. But extracting them efficiently and sustainably has been a challenge. Now, researchers have turned to Natural Deep Eutectic Solvents (NADES) as a green solution, using agro-industrial by-products like molasses grass, black corn cobs, and grape skins as raw materials.

Using a simplex-centroid mixture design and Response Surface Methodology, the team optimized a NADES blend of sorbitol, citric acid, and glycine. The results were striking: for black corn cobs, the extraction reached 54.20 mg/100 g under optimized conditions. While conventional solvents performed better for grape skins, NADES proved competitive and far more environmentally friendly, scoring an AGREE index of 0.73 versus 0.58 for conventional methods.

The real test came when the extracts were incorporated into yogurt and moisturizing gel formulations. Yogurts maintained stable physicochemical properties and color, while gels showed good homogeneity and chromatic stability. This means NADES can effectively recover natural colorants from waste, offering a sustainable path for food and cosmetic products.

Key Points

• NADES extracts anthocyanins from agro-industrial by-products efficiently.
• Black corn cobs yielded 54.20 mg/100 g under optimized conditions.
• NADES scores higher environmental sustainability (AGREE 0.73 vs 0.58).