Starch Based Nanocomposites in Active Packaging for Extended Shelf Life of Fresh Fruits

Abstract

Starch based packaging materials are made from cassava starch with increased antimicrobial activity of titanium dioxide (TiO₂) and zinc oxide (ZnO) nanoparticles. The objectives of this work were to evaluate the quantities of cassava starch, vinegar, glycerin, and water used for 10×10 cm² sheet film molding, and to investigate the antimicrobial activity of starch-nanoparticles based films. TiO₂ and ZnO nanoparticles were added into an aqueous starch solution at 0.01, 0.03, and 0.05 %w/w. The antimicrobial activity testing indicated that no inhibition zone against microorganisms was observable for film without the incorporation of nanoparticles. Inhibition areas were yielded by films coated with all concentrations of TiO₂ and ZnO (10 mm for 1×1 cm² and 20 mm for 2×2 cm² dimensions of films). The results showed that starch films mixed with 0.01 %w/w of TiO₂ were able to extend the shelf life of bananas from 5 - 7 days to 14 days, and tomatoes from 7 - 10 days to 21 days. The biodegradation test of starch film was carried out under the real condition of landfills. The result showed that all starch based films appeared to decompose in the soil within 14 days. The UV-vis spectrum of soil from landfill area containing nanoparticle-starch composites showed no TiO₂ or ZnO absorbance spectra; there was no nanoparticle residue in soil. Starch based nanocomposite films could be used for active packaging applications for post-harvest produce.