Biogenic Co3O4-embedded polycaprolactone nanocomposites for sustainable active food packaging applications

This study addresses the development of active and intelligent food packaging as a sustainable alternative to petroleum-based plastics. The innovation lies in the eco-friendly biosynthesis of tricobalt tetroxide nanoparticles (Co 3 O 4 -NPs) by green synthesis route using Ginkgo biloba extract, thereby eliminating harsh reagents, and in the comparison of two methods for incorporating Co 3 O 4 -NPs into a polycaprolactone (PCL) matrix (i.e., direct electrospinning and immersion) at concentrations of 5% and 10% by weight. Regarding methodology, the materials were analyzed using structural, mechanical, ecological, and microbiological techniques. Mechanical results indicated that incorporating 5% Co 3 O 4 -NPs by electrospinning refined the fibers and acted as a reinforcement, significantly increasing tensile strength, elasticity, and ductility. In contrast, the 10% Co 3 O 4 -NPs concentration resulted in agglomeration and a loss of mechanical performance. Additionally, UV radiation tests showed that films with 5% Co 3 O 4 -NPs underwent accelerated degradation, whereas those with 10% Co 3 O 4 -NPs protected the PCL. Regarding biocompatibility, VERO cell tests confirmed the biological safety of the PCL@Co 3 O 4 -NPs. Notably, the potential disposal of PCL@Co 3 O 4 -NPs proved safe: no seed phytotoxicity was observed, and soil tests demonstrated safe degradation with controlled cobalt release. From a microbiological perspective, the PCL@Co 3 O 4 -NPs inhibited pathogen formation, significantly reducing P. aeruginosa biofilm, particularly at the 10% Co 3 O 4 -NPs concentration. Therefore, the formulation with 5% Co 3 O 4 -NPs is the most promising and balanced alternative, as it optimizes mechanical performance, biocompatibility, and sustainable degradation for active packaging.