Cold plasma treatments for improvement of the applicability of defatted soybean meal-based edible film in food packaging

This study investigated the effects of cold plasma treatment (CPT) using various plasma-forming gases on the physical properties of defatted soybean meal (DSM)-based edible film (DSM film). The effect of packaging smoked salmon using a cold plasma (CP)-treated DSM film on the storage stability of salmon was also evaluated. DSM film was formed by casting film-forming solutions (DSM/glycerol at a ratio of 10: 3) prepared by high-pressure (172 MPa) homogenization. Among the O-2-, N-2-, air-, He- and Ar-CPTs, Ar-CPT, which increased elongation and lightness of the DSM film, was optimized against tensile strength, elongation, and water vapor permeability using a response surface analysis. Optimal plasma generation time and power were predicted as 15 min and 400 W, respectively. The tensile strength, elongation, and moisture barrier property of DSM film increased by 6.8%, 13.4%, and 24.4%, respectively, after CPT at optimal conditions. The CPT formed DSM film that decomposed easily and retarded lipid oxidation and hardness reduction of smoked salmon during storage at 4 degrees C. The results from this study suggest the use of CPT for improving the applicability of DSM film in food packaging. (C) 2016 Elsevier Ltd. All rights reserved.