Metabolic composition and bioactive potential of extracts from cocoa and coffee by-products: a systematic review

Coffee and cocoa processing generates large volumes of underutilized residues such as husks, pulps, and spent grounds (80%-90% of the fruit). The improper disposal of these materials contributes to environmental and socio-economic challenges, driving interest in circular economy strategies aligned with the United Nations Sustainable Development Goals. Although previous studies have described the metabolite composition of extracts from coffee and cocoa by-products, none has comprehensively examined their metabolomic diversity, bioactive potential, and shared metabolic features. As a key contribution, this review provides the most up-to-date curated dataset of metabolites reported in both coffee and cocoa agro-industrial residues, summarizing the analytical approaches used for metabolite identification and discussing annotation challenges. Critically, this review assesses the available evidence on biological activities and identifies shared metabolic features that may support future valorization strategies.