University of Tehran Press Iranian Journal of Biosystem Engineering 2008-4803 49 4 2019 02 20 Production of Biodegradable Packaging Material Based on Starch-kefiran-ZnO: Physical and Mechanical Characterization Production of Biodegradable Packaging Material Based on Starch-kefiran-ZnO: Physical and Mechanical Characterization 557 565 70006 10.22059/ijbse.2018.240115.664980 FA Iman Shahabi-Ghahfarrokhi Assistant Professor, Department of Food Science and Engineering, Faculty of Agriculture, University of Zanjan, Zanjan, Iran Amin Babaei-Ghazvini Graduated MS Student, Islamic Azad University, Tehran Branch, Tehran, Iran Journal Article 2017 09 16 In this study, biodegradable film based on starch-kefiran-ZnO was made by casting method. The produced films contain different content of nano ZnO (ZN) (1%, 3%, and 5% wt.). Also ZN dispersed by ultrasonic homogenizer and added to the starch-kefiran solution. Surface characteristics, thickness, moisture content, water vapor permeability and mechanical properties were investigated. In the images of water droplets, it was observed that the contact angle of starch-kefiran was 89.67 degrees. By increasing the amount of zinc oxide nanoparticles up to 1%, the contact angle increased significantly to 95.63 degrees, which means improving the surface properties and hydrophobicity. The water vapor permeability for starch-kefir film (×10⁻¹⁰ g m^-1s⁻¹Pa⁻¹) was 3.12, which was increased to 2.03 (×10⁻¹⁰ g m^-1s⁻¹Pa⁻¹) by increasing the concentration of zinc oxide up to 3%. Tensile strength and Young’s modulus of the specimens were increased by increasing ZN content up to 3%. On the other hand, elongation at break of the nanocomposites was decreased, simultaneously. It is obvious that, ZN was improved some of the packaging properties of the starch-kefiran film. In this study, biodegradable film based on starch-kefiran-ZnO was made by casting method. The produced films contain different content of nano ZnO (ZN) (1%, 3%, and 5% wt.). Also ZN dispersed by ultrasonic homogenizer and added to the starch-kefiran solution. Surface characteristics, thickness, moisture content, water vapor permeability and mechanical properties were investigated. In the images of water droplets, it was observed that the contact angle of starch-kefiran was 89.67 degrees. By increasing the amount of zinc oxide nanoparticles up to 1%, the contact angle increased significantly to 95.63 degrees, which means improving the surface properties and hydrophobicity. The water vapor permeability for starch-kefir film (×10⁻¹⁰ g m^-1s⁻¹Pa⁻¹) was 3.12, which was increased to 2.03 (×10⁻¹⁰ g m^-1s⁻¹Pa⁻¹) by increasing the concentration of zinc oxide up to 3%. Tensile strength and Young’s modulus of the specimens were increased by increasing ZN content up to 3%. On the other hand, elongation at break of the nanocomposites was decreased, simultaneously. It is obvious that, ZN was improved some of the packaging properties of the starch-kefiran film. https://ijbse.ut.ac.ir/article_70006_0e427848c7c9be6a98d6a045bf266db8.pdf