Evaluation of nanocomposite packaging containing Tio2 and ZnO on shelf life and quality changes of apple and grape

The aim of this work was to achieve of technological knowledge of production of antimicrobial nanocomposite packaging containing nanoparticles in order to increase the shelf life of apple and grape fruits. Low density polyethylene (LDPE) was chosen as base polymer and titanium dioxide (TiO2, 0, 0.5 and 1.5%) and zinc oxide (ZnO, 0, 0.75 and 1.5%) nanoparticles were added to LDPE matrix to produce nanocomposites by extrusion method. At the first step, the effect of nanoparticles addition on physicochemical properties of nanocomposites were investigated. It was revealed that the antimicrobial analysis showed that the nanocomposite films have good bactericidal activity and the effect of titanium dioxide is more than zinc oxide nanoparticles. At the second step, fabricated films were used for packaging of fresh apple and grape fruits. The qualitative parameters of fruits were investigated during this period. Results indicated that the weight loss of fruits decreases by using nanocomposites. Browning index and also, hardness of apple products in nanocomposite packaged samples were more than control ones. Nanocomposite films controlled the microbial count of apple and grape and the film containing 1.5% titanium dioxide showed the most effect on mesophilic bacteria and yeasts and molds. Generally, titanium dioxide was more effective than zinc oxide in both of improving physical properties of nanocomposites and increasing the shelf life of apple and grape fruits. Resoles of this research approved that the using of LDPE nanocomposite active film containing titanium dioxide and zinc oxide nanoparticles could be a good way for increasing the shelf life of apple and grape during production and distribution.