A hydroxypropyl methylcellulose/hydroxypropyl starch nanocomposite film reinforced with chitosan nanoparticles encapsulating cinnamon essential oil: Preparation and characterization.

Active packaging derived from polysaccharides plays an important role in prolonging the shelf life of food. In this study, cinnamon essential oil (CEO)-loaded chitosan nanoparticles (CNs) were prepared and embedded in hydroxypropyl methylcellulose (HPMC)/hydroxypropyl starch (HPS) blends to enhance the physicochemical and biofunctional properties of the formed films. Different concentrations (5, 10, 15, and 20 μL/mL) of CEOs were encapsulated with CNs to form CEO-CNs, as confirmed by Fourier Transform Infrared Spectrometer (FTIR), X-Ray Diffraction (XRD), and scanning electron microscope (SEM) images. The prepared CEO-CNs were incorporated into the HPMC/HPS film-forming matrix to prepare reinforced nanocomposite films. SEM images showed that the CEO-CNs were dispersed in the HPMC/HPS matrix, thus filling the void space in the composite matrix and significantly improving the mechanical and barrier properties of the bio-nanocomposite films. The elongation at break of the reinforced films improved from 8.54 ± 0.53 MPa to 24.81 ± 0.47 MPa, and the water vapor permeability was reduced by nearly 30 %. FTIR and XRD analyses indicated the formation of hydrogen bonds between CEO-CNs and HPMC/HPS polymer molecules. Release studies showed that the nanocomposite film was capable of sustained release of CEO, which imparted antioxidant (radical scavenging activity of 27.66-42.19 %) and antimicrobial properties (inhibition of Escherichia coli and Aspergillus flavus growth). Therefore, these HPMC/HPS nanocomposite films with enhanced properties may have great potential for food preservation.