Effect of SiO₂ nanoparticles in the physicochemical, mechanical, and structural properties of sweet potato starch edible films

This study aimed to evaluate the effect of SiO₂ nanoparticles on the mechanical, structural, and physicochemical properties of sweet potato (Ipomoea batatas) starch edible films. Two edible films were made, films without SiO₂ nanoparticles (EF), and films with SiO₂ nanoparticles (DEF). The tensile strength for EF and DEF was 23.79 MPa and 24.65 MPa, respectively, and the elasticity for EF and DEF was 1.53% and 1.13%, respectively. The water vapor permeability, solubility, and water absorption for EF were 2.2 x 10^-9 g/m·s·Pa, 19.52% and 4.51%, while for DEF they were 1.7 x 10^-9 g/m·s·Pa, 18.19%, and 3.03%, respectively. According to FTIR results, the SiO₂ nanoparticles increased the short-range crystallinity of starch and reduced water vapor permeability without affect its mechanical properties.

Keywords: solubility, permeability, elasticity, tensile strength, crystallinity.