Cocoa waste valorization: a review and sustainability analysis of green technologies

Abstract

Cocoa residues – notably cocoa pod husks and cocoa bean shells – can be valorized for biocompound recovery, bioenergy production, and waste reduction. This review analyzed 1115 publications related to this field to identify key research trends. Interest is increasing in compounds such as theobromine, bioactive substances, adsorption processes, and byproducts like biogas. Terms including ‘biomass’, ‘biogas’, ‘theobromine’, ‘cocoa pod husk’, and ‘cocoa shell’ emerged as central themes, along with extraction methods and sustainability. The environmental impact of three extraction methods – ultrasound (US), supercritical water extraction (SWE), and natural deep eutectic solvents (NADES) – was assessed using the Path2Green sustainability metric. Their respective scores were −0.386 for US, −0.05 for SWE, and 0.341 for NADES. The results highlight cocoa waste valorization as a growing field, driven by sustainability and circular economy goals.