Plasma technology as a tool to decrease the sensitivity to water of fish protein films for food packaging

Proteins films have been developed for use in food packaging materials in order to replace synthetic polymers because of environment pollution. Despite their advantages, the use of protein films in a wide range of food products is still limited due to their hydrophilic behavior. Thus, this study aimed to decrease the sensitivity of fish protein films to water through the application of glow discharge plasma. Plasma parameters (power, pressure and time of exposure) were studied according to a 23 factorial design, and the physicochemical properties of the films including moisture content, water vapor permeability, and solubility in water were evaluated. The microstructure and thermal properties of the films were also characterized. In general, glow discharge plasma caused different effects in films properties, such as cleaning and etching which were responsible for the changes observed in physicochemical properties. Power and time of exposure, as well as their interaction, were the most influent parameters. Decrease in water vapor permeability and solubility were observed in some treatments, which are important characteristics for a material to be used as food packaging. Then, the plasma setting might be changed through the adjustment of parameters of exposure according to the specificity of the application intended.