Abstract We prepared bilayer films of iron yam–pea starch and corn zein to evaluate their potential application in the packaging of instant foods and condiments. We found that the water resistance and mechanical properties of bilayer films were improved after adding a layer of corn zein compared with the monolayer films of the starch materials. Scanning electron microscopy revealed that the bilayers were close and this was reflected in increased thermal stability and biocompatibility between layers with the addition of zein. Our experimental films showed greater elongation at break than the commercial biaxially oriented polypropylene polyethylene films. Based on the results of this study, the iron yam-pea starch/corn zein films have the mechanical strength and flexibility to be used for convenience food packaging materials, which are expected to provide consumers with clean products.

Abstract Lemon essential oil was used as plasticizers to prepare iron yam/maize starch edible films. Changes of physical, microcosmic and antimicrobial properties of films were studied. Results showed that the addition of lemon essential oil led to the decrease of moisture content, transparency, whiteness index, water vapor permeability, solubility and tensile strength and the increase of b*, elongation and haze values. With the increase of lemon essential oil content, the antibacterial activity increased, and the surface and internal microstructure of the film became more and more heterogeneous. Compared with the control group, the tensile strength, water content and WVP of IYM/2LO films decreased by 21.9%, 23.5%, and 23.6%, respectively. When surfactant was added, the antimicrobial activity, solubility, haze, surface coarseness and porosity increased significantly, and the tensile strength decreased from 11.8MPa (IYM/1LO) to 7.60MPa (IYM/1LO/0.1S) obviously. The iron yam/maize starch edible films with good physical and antibacterial properties can be considered as convenient food flavoring packaging materials.