Development of Active Chitosan Film Based on Bacterial Cellulose Nanofiber Incorporated With ZnO Nanoparticles for Monitoring Hamburger Spoilage

Food safety is a global concern due to the dangers posed by microbial pathogens, toxins, and food spoilage. Hence, antibacterial and antioxidant compounds have been widely studied for food packaging. This research was aimed at the effect of chitosan (C) film containing bacterial cellulose (BC) nanofibers and zinc oxide (ZnO) nanoparticles (NPs) on the hamburger shelf life. Four types of films including C, chitosan + bacterial cellulose (C-BC) nanofibers, and chitosan + bacterial cellulose nanofiber + zinc oxide nanoparticle at two concentrations of 1% (C-BC-ZnO NP-1) and 2% (C-BC-ZnO NP-2) were prepared. The results showed that adding of ZnO NPs decreased the thickness and water vapor permeability, increased the opacity, and improved the mechanical properties and thermal stability of films (p < 0.05). C-BC-ZnO NP-1 had higher tensile strength, elongation at break, modulus of elasticity (ME), and melting temperature (T_m) than other nanocomposites. A scanning electron microscope (SEM) showed a good distribution of ZnO NPs in the film matrix. The nanocomposites had a significant effect on the chemical and microbial characteristics of hamburger. The lowest pH; total volatile nitrogen (TVN) compounds; peroxide value; thiobarbituric acid; and the total count of mesophilic and psychrophilic bacteria, mold, and yeast population were observed in C-BC-ZnO NP-1 and C-BC-ZnO NP-2 groups (p < 0.05). In the sensory evaluation, the nanocomposite containing 1% ZnO NPs showed higher overall acceptance than 2%. In general, adding ZnO NPs improves the physical properties of C film and can be used as active packaging in meat products.