Polylactide/poly(ε-caprolactone)/zinc oxide/clove essential oil composite antimicrobial films for scrambled egg packaging

The aim of the present work was to develop an antimicrobial nanopackaging for food application by incorporating zinc oxide (ZnO) nanoparticles and clove essential oil (CEO) into polylactide/polyethylene glycol/polycaprolactone (PLA/PEG/PCL) blend using the solution cast technique. The developed films were characterized by thermal, rheological, mechanical, structural and microbiological analysis. Rheological tests at melt revealed that reinforcement of ZnO significantly lowered the dynamic moduli by accelerating the polymer degradation. The CEO acts as an efficient plasticizer by facilitating the chain mobility in the blend, which reflected into the tensile and thermal properties. Reinforcement of ZnO into the PLA/PEG/PCL matrix did not change the thermogram. The efficacy of the composite films was verified against Staphylococcus aureus and Escherichia coli inoculated in scrambled egg, and results indicated that the PLA/PEG/PCL/ZnO/CEO film exhibited the highest antibacterial activity during 21 days storage at 4 °C. The Weibull model was employed to fit the inactivation kinetics of the test organisms, and it was found that the model fitted well for the developed packaging materials.