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.

Polysaccharide-Based Packaging Functionalized with Inorganic Nanoparticles for Food Preservation

“…According to the literature [1,3,17,37,38], dipping food products in a film-forming aqueous solution is the most common method to apply organic-inorganic hybrid films (Figure 3a), followed by developing hybrid materials by the evaporative casting method and then applying them as a coating (Figure 3b).…”

“…Figure 4 is a proposal diagram to develop polysaccharide-based materials functionalized with inorganic nanoparticles based on the information discussed throughout this work. This kind of hybrid materials are recognized as a promising alternative to fabricate food packaging because they are non-toxic, eco-friendly, low-cost, available, biodegradable, and simple to prepare [1,3,11,12,37,38]. Additionally, the most reported inorganic nanoparticles used as nanofillers for the functionalization of polysaccharide-based packaging used for food preservation are zinc oxide, titanium dioxide, silver, silicon dioxide, iron oxide, zirconium, halloysite, montmorillonite, and magnesium oxide, as discussed below.…”

“…Tunma [37] reported that a cassava starch-titanium dioxide hybrid film effectively extends the shelf life of bananas (14 days) and tomatoes (21 days) compared to those packaged with plastic films (5 and 10 days, respectively). Furthermore, Abdel-Baky et al [72] informed that guar-gum films functionalized with TiO 2 can preserve quality parameters of dates for eight weeks stored at 0 • C without minimal changes in the fruit weight, color attributes, total soluble solids, acidity, and phenol and flavonoid contents.…”

“…Moreover, treated fruit maintained an adequate microbial safety (yeast and molds) compared with guar-xanthan-lemongrass essential oil coat. According to the authors, these behaviors were attributed to the low oxygen/high carbon dioxide microclimate generated by the guar gum-titanium dioxide hybrid film that directly slow some metabolic processes, preventing dehydration and microbial deterioration of dates [37,72]. Furthermore, Tian et al [68] preserved Ginkgo biloba seeds up to 180 days (1 • C) by coating them with chitosan-titanium dioxide films.…”

“…Figure 3. Application of organic-inorganic hybrid film for food preservation by dipping (a) and coating (b) methods (adapted from Tunma[37] and Anugrah et al[39]). …”