Thorough evaluation of sweet potato starch and lemon-waste pectin based-edible films with nano-titania inclusions for food packaging applications

Biodegradable starch-pectin-titanium oxide nanoparticles (TiO2 - NPs) blend edible films were developed by casting filmogenic solution of sweet potato starch and lemon waste pectin incorporated with TiO2 nanoparticles. The effect of incorporating different concentration of TiO2 nanoparticle (0.5-4% wt) on the different properties of starch and pectin based edible film was evaluated. Surface color measurement, light transmission, scanning electron microscopy, fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and thermogravimetric analysis techniques were used to characterize the developed films. Increasing the level of TiO2-NPs led to significant decreases in the moisture content, solubility, and moisture uptake of the films. Addition of low concentration of TiO2 - NPs into starch-pectin films significantly improved the mechanical and moisture barrier properties. SEM analysis also revealed that good particles dispersion could be obtained when nano-TiO2 particles content was low (0.5-2% wt). The glass transition temperatures (Tg) shifted to higher temperature with increasing the TiO2 concentrations and the thermal stability of the films was increased. The transmittance percentage was also decreased with increasing the TiO2 concentrations which revealed that with UV prevention capacity, the developed films can be used as food grade UV screening biodegradable packaging material. (C) 2019 Elsevier B.V. All rights reserved.