Preparation and characterization of functional sodium caseinate/guar gum/TiO2/cumin essential oil composite film

Eco-friendly functional bionanocomposite films were prepared using sodium caseinate (SC) and guar gum (GG) as the polymer matrix and TiO2 and cumin essential oil (CEO) as functional fillers. 0.2 vol% GG selected for the preparation of SC/GG composite film and various amount of TiO2 and CEO (1 and 2 wt% based on SC) were incorporated into the SC/GG film either individually or in combination. The addition of TiO2 and CEO significantly improved the water permeability and sensitivity properties and mechanical characteristics such as the strength (TS), stiffness (YM), and flexibility (EB) of the composite films. Also, the SC/GG films incorporated with TiO2 and CEO exhibited remarkable antibacterial activity against both Gram-positive (L. monocytogenes and S. aureus) and Gram-negative (E. coli O157: H7 and S. enteritidis) bacteria. All the film properties were varied not only on the concentration of TiO2 and CEO, but also increased synergistically when they were added together.