Development and optimization of sustainable and functional food packaging using false banana (Enset) fiber and zinc-oxide (ZnO) nanoparticle-reinforced polylactic acid (PLA) biocomposites: A case of Injera preservation

Abstract

In a global context marked by food insecurity, it is essential for food science and packaging technology researchers and stakeholders to ensure the availability of safe and adaptable foods with minimal environmental impact. Achieving sustainability in food packaging requires multiple approaches, including the use of natural and biodegradable materials including cellulosic fibers. The current study aimed to develop and characterize and optimized an effective biocomposite food packaging/storing materials, specifically for a popular Ethiopian flatbread called injera, made from a grain called ‘Teff’ (Eragrostis tef). The proposed biocomposite food storage and packaging was designed by incorporating fiber-reinforcing materials, namely false banana, also called Enset fibers (EFs), and ZnO nanoparticles (ZnO NPs) into a polylactic acid (PLA) matrix. A central composite design (CCD) approach was used to evaluate the impact of the reinforcing Enset fibers (EFs) at 5 %, 15 %, and 25 % and ZnO NPs at 0 %, 5 %, and 10 % levels. The developed functional biocomposite packaging materials were tested and characterized for various properties, including mechanical strength, water activity, antifungal activity, and migration properties. The results showed that the inclusion of ZnO NPs improved the tensile strength, migration, and barrier properties, while the reinforcing fiber enhanced mechanical and migration properties but reduced barrier properties. The combined effect of the reinforcement fibers (EFs) and ZnO NPs led to further improvements in the mechanical strength and migration properties, though no interaction effect was observed on barrier properties. The optimal solution, consisting of 6.7 % ZnO nanoparticles and 6 % Enset fibers, resulted in a highly effective packaging and storage prototype that extended the freshness of the food for over eight days.