Structure, mechanical and physical properties of hordein/chitosan composite films

In this study, edible films (HCHs) based on hordein/chitosan complexes were prepared by the drop cast method, and the effects of the composite packaging films on strawberry preservation were evaluated. The micrographs of hordein/chitosan composite films presented more compact structure than chitosan film. Fourier transform infrared spectroscopy results demonstrated that chitosan and hordein interacted with each other by hydrogen bonding in the composite films. The thermal stability and the tensile strength of hordein/chitosan films significantly increased with gradual addition of hordein(the ratio of hordein to chitosan, from 0:1 to 1:5). While elongation at break, water vapor permeability, water solubility and moisture content of the composite films obviously decreased with the increasing hordein content(the ratio of hordein to chitosan, from 0:1 to 1:5). The composite film HCH5 exhibited the best mechanical and water resistance properties. However, further addition of hordein (HCH3) led to the decrease of the mechanical and physical properties of the composite films. Additionally, the composite film HCH5 showed the most effective preservation on strawberry fruits during 72 h storage at room temperature.