The various sizes (15, 30, 80, and 100 nm) of nano-SiO₂/potato starch films were synthesized and characterized. The gas permeability, antibacterial properties, and mechanical properties of the films were evaluated to their potential for application as food packaging materials. Results indicated that the 100 nm nano-SiO₂ was well dispersed in the starch matrix, which induced an active group on the surface of 100 nm nano-SiO₂ adequately combined with starch macromolecule. The water resistance and mechanical properties of the films were improved with the addition of nano-SiO₂. Notably, resistance to ultraviolet and thermal aging was also enhanced. The nano-SiO₂/potato starch films were more efficient against Escherichia coli (E. coli) than Staphylococcus aureus (S. aureus). Remarkable preservation properties of the films packaging the white mushrooms were obtained, with those of the 100 nm films considered superior. This study can significantly guide the rational choice of the nano-SiO₂ size to meet the packaging requirements of various agricultural products.
Keywords: antibacterial property; nano-SiO2; potato starch films; size.