Introduction. Polyphenols have received significant attention inrecent years due to their antioxidant capacity and their significant role in diseaseprevention. Cocoa is one of the major naturally occurring sources of antioxidants,particularly of polyphenolic compounds. Materials and methods. Gelatinnanoparticles loaded with a cocoa-derived polyphenolic extract were synthesized bynanoprecipitation. The nanoparticle synthesis was performed using a central compositeexperimental design that allowed for the assessment of how gelatin concentration andsurfactant concentration (Tween 80) affected the hydrodynamic diameter and polydispersityof the particles. The nanoparticles were characterized using dynamic light scattering(DLS), assessments of zeta potential, scanning electron microscopy (SEM) and Fouriertransform infrared spectroscopy (FT-IR). Results. The analyses demonstratedthat the nanoparticles examined exhibited hydrodynamic diameters of (100 to 400) nm,polydispersity indices of less than 0.2 and average zeta potential values of 29–33 mV. SEMimages revealed that most nanoparticles were spherical and uniform in morphology, withaverage sizes less than 250 nm. In vitro experiments in which the2,2-diphenyl-1-picrylhydrazyl (DPPH) method was used to assess the prevalence of freeradical-scavenging ability among these nanoparticles indicated that the loading efficiencyfor the nanoparticles was approximately 77.56%. Conclusion. Nanoparticlesloaded with polyphenolic extract were obtained with average sizes ranging from (120 to250) nm and largely spheroidal morphologies. Polymer and surfactant concentrationssignificantly influenced the hydrodynamic diameters and polydispersity indices of theparticles. The incorporation of the polyphenolic extract into the polymer matrix enabledthe preservation of the antiradical activity of the bioactive compound.