Characterization of hydroxypropyl methyl cellulose-whey protein concentrate bionanocomposite films reinforced by chitosan nanoparticles

In the current study, some physicochemical, mechanical, thermal, structural, and antibacterial properties of hydroxypropyl methyl cellulose-whey protein concentrate (HPMC-WPC) film loaded with chitosan nanoparticles (CNPs) are scrutinized. Initially, the optimal ratio of HPMC:WPC (70:30) was screened, then CNPs loaded into the HPMC:WPC blend film at the levels of 1%-5%. Well compatibility of the blend film components and generation intermolecular interactions were demonstrated by Fourier transform infrared and X-ray diffraction tests, respectively. A uniform distribution of CNPs within the film structure was monitored by scanning electron microscopy micrographs. The DSC scans showed an upgrading in thermal characterizations of the blend film as a result of CNPs addition. As well, the water vapor permeability and flexibility of bionanocomposites decreased, while the tensile strength improved considerably (p < .05). The antibacterial effects of CNPs was more evident on Gram-positive (Listeria monocytogenes and Staphylococcus aureus) rather than Gram-negative (Escherichia coli) bacteria. Practical applications The current research would have various uses in the area of food packaging. Bio-based packaging films are developed to substitute petrol-based materials for health and ecological reasons. Nanoparticle loading and blending of plant-based biopolymer films are strategies can strength their physical, mechanical, structural, and antibacterial attributes.