Preparation characterization and biodegradation studies of novel active poly 3 hydroxybutyrate nanocomposite films and their application in packaging fresh produce

Abstract

The rising environmental concerns associated with non-biodegradable petrochemical-based food packaging underscore the critical need for sustainable alternatives. Poly (3-hydroxybutyrate) (PHB), a natural polyester of microbial origin has excellent potential for food packaging applications owing to its renewability, high crystallinity, biocompatibility, biodegradability, and physical attributes comparable to conventional plastics. Nonetheless, PHB has certain shortcomings, including low elongation at break, moderate gas barrier properties, and negligible antimicrobial and antioxidant activities for its direct application in food packaging. Observing these facts, our work focused on overcoming the limitations of PHB by combinational loading of essential oil and nanofiller, evaluating the suitability of developed PHB-based nanocomposite films for storing fresh produce and assessing the biodegradability of these films in natural environmental conditions viz. soil and river water. Firstly, five different chemical synthesis routes (precipitation, sonication-precipitation, microwave combustion, conventional combustion, and solvothermal processes) were screened to customize the properties of MgO nanoparticles (NPs) for their reinforcement in PHB. Wherein, the microwave combustion route yielded MgO NPs with higher specific surface area (67.32 m2/g), smaller particle size (5-35 nm), and outstanding antimicrobial and antioxidant activities compared