<p>Development of biodegradable food packaging materials is one of the most promising ways to reduce plastic waste and contribute to the circular economy. Water-insoluble, film-forming proteins from natural sources obtained as industrial by-products, e.g. corn protein zein, exhibit a great potential in this respect, where it is highly desirable to avoid any safety and environmental concerns coming from organic solvents used for zein dissolution. Here, zein films were prepared by casting water-based dispersions of zein nanoparticles which coalesce during the drying step to produce continuous zein film. Colloidal stability of the dispersions was evaluated and a theoretical model for charging zein nanoparticles was proposed. Plasticizing effect of different polyols (propylene glycol, glycerol, polyethylene glycol 200 and 600) on zein film properties was investigated. The obtained plasticized zein films were characterized for structural, mechanical, optical and barrier properties and were benchmarked against unplasticized zein films. It was found that zein dispersions were stable over six weeks and that continuous zein films could be obtained by casting and drying the dispersions with or without plasticizer. Plasticized films, except glycerol plasticized film, showed improved structural, optical and mechanical properties, while the films’ water susceptibility was increased due to hydrophilic nature of used plasticizers.</p>