Pengembangan bionanokomposit film berbasisi pati tapioka dan nanopartikel ZnO dengan plasticizer gliserol

Abstract

Cassava starch is able to form transparent coatings and flexible films without using any chemical additives. However, films made from cassava starch only is poor in functional packaging properties. The main objective of this study was to enhance functional packaging properties of casava starch films by using zinc oxide nanoparticles (ZnO-NPs) as reinforcing agent, and glycerol as plasticizer. Cassava starch/ZnO nanocomposite films were prepared at 4 levels of ZnO-NPs (0.25, 0.5, 1.0, 3.0 % by weight of starch) and 15 % of glycerol by weight of solid (cassava starch + ZnO-NPs). In this study, plasticized starch-ZnO nano-composite filmss were prepared by nanodispersion technique followed by solution casting method, and were analysed to determine its mechanical properties by tensile tests, the glass-transition temperature (Tg) by differential scanning calorimetry (DSC) and antimicrobial properties against three bacterial strains that commonly contaminate food products, e.g. Escerichia coli, Bacillus cereus and Staphylococcus aureus. The improvement in mechanical properties could be achieved with plasticization and ZnO-NPs incorporation. The incorporation of ZnO-NPs 3 % significantly induced antibacterial activities of the cassava starch films against Escherichia coli, Bacillus cereus, Staphylococcus aureus. Moreover, the glass-transition temperature of cassava starch increased with the increasing ZnO-NPs concentrations. Our results suggest that cassava starch films containing ZnO-NPs could be used as antibacterial food packaging material