Approche durable de la cosmétique : Valorisation des déchets agroalimentaires par extraction verte et formulation d’une crème antioxydante et anti-âge

Abstract

This study aims to valorize plant waste, particularly orange and pomegranate peels, as natural sources of bioactive compounds with strong antioxidant and antibacterial potential. A comparative study was carried out using two maceration extraction methods: conventional ethanol extraction and green extraction using a natural deep eutectic solvent (DES) composed of glycerol and lactic acid. Phytochemical analysis by HPLC revealed the presence of polyphenols, tannins, coumarins, and triterpenes, highlighting the chemical richness of the extracts obtained by both methods. Antioxidant activity tests (DPPH and FRAP) showed that the DES extracts exhibited comparable or even superior activity to ethanolic extracts. Antibacterial assays performed on Escherichia coli and Staphylococcus aureus demonstrated the high efficacy of DES extracts, particularly those from pomegranate peel. Furthermore, the combination of orange and pomegranate peel extracts revealed a synergistic effect, enhancing biological activity beyond that of orange extract alone, though slightly lower than that of pomegranate alone. This suggests a complementary action of the active compounds in the mixture. Based on these results, a cosmetic cream with brightening and anti-aging properties was formulated using the DES-derived extract mixture. The final product showed a skin-compatible pH (5.9), an oil-in-water (O/W) emulsion, a homogeneous texture, and excellent skin tolerance, as confirmed by volunteer testing. This work highlights the value of natural deep eutectic solvents as sustainable alternatives to conventional solvents and underlines the potential of bioactive compounds derived from agro-industrial waste in the formulation of innovative cosmetic products, especially when used synergistically