Influence of zno nanoparticles and stearic acid on physical, mechanical and structural properties of cassava starch-based bionanocomposite edible films

Bionanocomposite consists of natural polymers and the filler of nanoparticles. The aim of this study was to evaluate the effect of zinc oxide (ZnO) nanoparticles (ZnO-NP) and stearic acid on characteristics of cassava starch (CS)-based bionanocomposite edible films. The experiment had 3x2 factorial experiment design (ZnO-NP: 0, 1, 2% and stearic acid: 0, 30% by weight of CS). Glycerol and tween 80 were used as the plasticizer and emulsifier respectively. The results showed the incorporation of ZnO-NP increased the thickness, color difference (?E), tensile strength and decrease elongation, water vapor transmission rate (WVTR) and crystalline percentage. While the addition of stearic acid increased the thickness, ?E and decreased tensile strength, elongation, WVTR, crystalline percentage compared to the cassava starch-based film. ZnO-NP was not observed clearly by using SEM and successfully trapped and coated by starch and stearic acid matrix. XRD showed an increase with the addition of 2% ZnO-NP in the polymers in the both cassava starch and cassava starch + stearic acid films. The C-H and C=O stretching was more intense for film with the addition of stearic acid compared to films without stearic acid by using FTIR. The improvement in mechanical and physical properties were achieved at CS + 2% ZnO-NP and CS + 2% ZnO -NP + 30% stearic acid respectively