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

The growing demand for clean-label products has intensified the search for natural and sustainable alternatives to synthetic colorants. Anthocyanins stand out as promising pigments due to their coloring capacity and bioactive properties. This study evaluated the efficiency of natural deep eutectic solvents (NADES) in extracting anthocyanins from agro-industrial by-products—molasses grass, black corn cobs, and grape skins—and their application in food and cosmetic matrices. A simplex-centroid mixture design with Response Surface Methodology was used to optimize solvent composition based on sorbitol, citric acid, and glycine. NADES showed high extraction efficiency, especially for black corn cobs, reaching 54.20 mg/100 g under optimized conditions. Although conventional extraction performed better for grape skins, NADES demonstrated competitive efficiency and superior environmental performance (AGREE index 0.73 vs. 0.58). The extracts were successfully incorporated into yogurt and moisturizing gel formulations. Yogurts maintained stable physicochemical properties and color, while gels showed good homogeneity and chromatic stability. These findings support the use of NADES as green solvents for recovering natural colorants from agro-industrial residues, with potential applications in sustainable food and cosmetic products.