Formulation and characterization of sustainable materials for food packaging: PLA-PHB blends modified with different types of corn oil

Innovation in sustainable food packaging involves designing advanced bio-based materials that combine performance, biodegradability, and safety of use. In this study, a novel polymer blend based on PLA and PHB was developed, modified with 10 wt% epoxidized corn oil (Eo) and 2,5 wt% maleinized corn oil (Mo), two bio-functionalized additives obtained from renewable resources. This innovative combination was designed to enhance compatibility between polymeric phases, overcoming traditional limitations in fragility, poor processability, and barrier properties. The materials were characterized through FTIR-Fourier Transform Infrared Spectroscopy, contact angle measurements, mechanical tests, optical analyses, water vapor permeability, and suitability tests for food contact with fresh persimmon fruits. The results demonstrate a significant modification of surface chemistry, with an increase in hydrophobicity and improved phase dispersion. The mechanical properties exhibit an optimized balance between stiffness and deformability, which is essential for packaging applications. Furthermore, the transparency and optical properties were found to be stable, making it visually suitable for food packaging. Particularly innovative is the direct application test on persimmons, which highlighted the absence of visible migration or organoleptic alterations, suggesting excellent suitability for direct contact with fresh foods. This research therefore proposes a bioinspired and circular approach, valorizing agricultural by products to formulate functional, biodegradable, and safe materials, in line with European directives for increasingly sustainable packaging.