Development of sustainable bioplastic films for food packaging using zein protein-derived amyloid fibrils: characterization and functional properties

Given the issues presented by plastic pollution, efforts have been directed toward advancing protein-derived bioplastics as environmentally friendly alternatives to conventional plastics. However, the drawbacks of protein-based bioplastics include poor mechanical properties, barrier performance, and wet stability. Due to the exceptional properties of amyloid fibrils, such as superior mechanical strength, high hydrophobicity, and outstanding chemothermal stability, they have been employed in producing environmentally friendly and renewable bioplastics. As amyloid fibrillogenesis has been recognized as a promising approach to reinforcing the properties of protein-based materials, our study focused on fabricating sustainable bioplastic films using zein protein amyloid fibrils (ZPAFs). The formation of ZPAF was verified using varying biophysical and spectroscopic tools, followed by synthesizing the bioplastic films by blending them with various additives, including polysaccharides, crosslinkers, and plasticizers. A variety of functional properties, such as surface microstructure, mechanical properties, thermal stability, water vapor barrier, surface wettability, antioxidant activity, and UV-blocking capability, of ZPAF-based bioplastic films were examined. Our results show that bioplastics with high ZPAF content conform to overall food migration regulations and have the potential for regeneration and reuse. This investigation demonstrates the feasibility of applying amyloid fibrils in fabricating sustainable and regenerative bioplastics for food packaging.