Abstract: Zein/chitosan composite films were prepared by casting after addition of zein to chitosan/acetic acid/ethanol mixed systems containing different concentrations of chitosan (CS) in order to improve the mechanical and hydrophilic properties of zein film. The effect of CS concentration on physicochemical properties and antibacterial activity of zein/chitosan composite films was investigated. Results indicated that the viscosity and conductivity of mixed solutions showed step-like changes with increasing CS concentration from 2% to 8%, and the properties of composite films were markedly affected by addition of CS, leading to an increase in elongation at break from 1.00% to 6.67%, a reduction in contact angle from 65.97° to 53.61°, and an elevation in water vapor transmission rate from 5.23 to 9.16 g·m /(m2·h·Pa). Scanning electron microscope observation indicated the composite films showed a smooth and homogeneous surface. Furthermore, the composite films possessed potent antibacterial activity against Escherichia coli.

Key words: zein, chitosan, microstructure, antibacterial