Simplifying revalorization of cocoa bean shells through new sustainable approaches

Cocoa bean shells (CBS) are an abundant agro-industrial by-product rich in lipids, methylxanthines, and phenolic compounds. The efficient and selective recovery of such compounds remains limited by the low specificity of conventional methods, combined with the challenging fractionation typically requiring adsorptive or membrane-based separations. Here, we develop a biorefinery strategy integrating supercritical CO 2 (scCO 2 ), a CO 2 -expanded 2-methyltetrahydrofuran (2-MeTHF) system, and a final liquid–liquid fractionation (LLF). First, scCO 2 enabled rapid recovery of the lipid fraction, yielding an extract enriched in fatty acids and sterols. Subsequently, Conductor-like Screening MOdel for Real Solvents (COSMO-RS) guided solvent screening identified 2-MeTHF as the optimal bio-based candidate for the simultaneous solubilization and partition of theobromine and epicatechin while ensuring biphasic behavior with water. Using water-saturated 2-MeTHF expanded with CO 2 enhanced mass transfer and diffusivity, producing an extract enriched in methylxanthines and phenolics. The subsequent LLF afforded a highly selective partitioning: theobromine migrated predominantly to the aqueous phase (85.64%), while epicatechin concentrated almost entirely in the 2-MeTHF-rich phase (91.35%). The proposed integrated strategy reduces overall solvent consumption and produces three distinct high-purity fractions, rather than a single crude extract. This approach enables a wider range of targeted applications and maximizes the valorization of agricultural residues for use in food, cosmetic, and pharmaceutical formulations. Moreover, by using Path2Green metric, the greenness of the developed process was assessed. Results demonstrate a versatile and scalable platform for greener and more efficient valorization of CBS. • Integrated biorefinery strategy for cocoa bean shell valorization. • scCO 2 enables selective recovery of the lipid fraction. • COSMO-RS screening identifies 2-MeTHF for selective recovery. • CO 2 -expanded 2-MeTHF extracts methylxanthines and phenolic compounds. • Liquid–liquid fractionation separates methylxanthines from phenolics.