Enhancing the Potential of Poly(hydroxybutyrate)/Poly(lactic acid) Films with Olive Oil and Zinc Oxide for Active Food Packaging

Abstract

AbstractTo tackle the persistent global issue of nonbiodegradable petro‐plastics, this study undertakes the challenge of developing environmentally sustainable and active packaging alternatives. The approach involves preparing composite films by blending poly(hydroxybutyrate) (PHB) and poly(lactic acid) (PLA) while integrating olive oil and zinc oxide to augment their effectiveness. The films are fabricated by mixing different concentrations of ZnO (0.5% to 2.5%) and 10% olive oil into PHB/PLA (70/30) matrix using solvent‐casting. A comprehensive analysis is conducted to assess the properties of prepared films, including Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, X‐ray diffraction, mechanical testing, water vapor permeability, and UV‐blocking properties. Among the tested samples, film containing 1.5% ZnO (referred to as PPOZ1.5) displays highest tensile strength (30.8 MPa) along with improved water vapor permeability. Consequently, PPOZ1.5 film is selected for further investigations which include DPPH (diphenyl‐picrylhydrazyl) radical scavenging activity, and antimicrobial activity. PPOZ1.5 film exhibits exceptional antioxidant activity (>65%) and significant antimicrobial efficacy against Escherichia coli, Staphylococcus aureus, and Aspergillus niger. Moreover, when utilized to package bread samples, PPOZ1.5 film effectively inhibits microbial growth, ensuring food safety for an extended storage period of more than 12 days, ultimately contributing to the preservation and safety of packaged bakery products.