Advanced Separation Technologies for Cascade Biorefinery Valorization of Capsicum Seed Residues

Capsicum seed waste is an underutilized agro-industrial biomass with considerable potential for the recovery of oils, proteins, phenolic compounds, capsaicinoids, peptides, and other value-added fractions. This study evaluates advanced separation technologies for valorization in a cascade biorefinery, with an emphasis on extraction yield, selectivity, product functionality, sustainability, and technological scalability. A systematic literature search was conducted in Scopus and Web of Science, and the retrieved records were merged and processed using R (version 4.6.1) in RStudio (version 2026.01.2+418) Study selection and presentation were aligned with the PRISMA protocol, resulting in 82 studies included for thematic analysis. The evidence indicates that ultrasound-assisted, enzymatic, aqueous oleosome, pressure-based, membrane, and chromatographic approaches can improve the recovery and selective separation of valuable seed-derived fractions. The reported experimental results include an oleosome recovery of 66.96% by weight, with a potential recovery approaching 90% by weight, and a 73.5% increase in extraction recovery after enzyme-assisted processing. Protein modification and fractionation have also demonstrated opportunities for the development of functional ingredients, bioactive fractions, and biomaterials. However, limited pilot-scale validation, process integration, standardization, techno-economic feasibility, and life-cycle assessments constrain industrial implementation. Future research must prioritize scalable, closed-loop cascade strategies to minimize energy use, solvent consumption, and environmental footprint while maximizing biomass conversion.