Effect of nanocomposite packaging containing Ag and ZnO on inactivation of Lactobacillus plantarum in orange juice

Nanocomposite LDPE films containing Ag and ZnO nanoparticles were prepared by melt mixing in a twin-screw extruder. Orange juice was sterilized and was inoculated with 8.5 log cfu/mL of lactobacillus plantarum. Packages prepared from nanocomposite films were then filled with this orange juice and then stored at 4 °C. Microbial stability of the juice was evaluated after 7, 28, 56, 84, and 112 days of storage. The results showed that microbial growth rate significantly reduced as a result of using this nanocomposite packaging material. Reduced numbers of L. plantarum were observed (p < 0.05) in nanocomposite packages of orange juice containing nanosilver and nano-ZnO. Moreover, packaging made from nanocomposite film containing nanosilver showed a more pronounced antimicrobial effects, as compared with nano-ZnO during 112 days storage of inoculated orange juice. However, LDPE + 5% P105 packages, showed a significant antimicrobial activity compared with others.