Characterization of Tragacanth- Locust Bean Gum Edible Film Blend

The objective of the present study was to investigate the structure and properties of a novel blend film made by mixing different ratios of Tragacanth (TG) and locust bean gum (LBG) using solvent casting method. To this end Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transparency analysis, moisture barrier and tensile strength evaluation were carried out. Also the rheological behaviour of TG and LBG solutions at different mixing ratios were investigated. The results of rheological studies demonstrated a distinct synergism between the two gums at all mixing ratios which was attributed to some intermolecular interactions as confirmed by FTIR spectra. Scanning electron microscopy showed a homogeneous and smooth surface morphology with no pores and cracks for the films. Physical analysis indicated that although the thickness and density of films were not affected by gum blending ratio, their transparency, water barrier and mechanical properties were inversely affected by increasing the proportion of TG. These results suggest that the films made from LBG and TG blend are promising enough to be considered for biodegradable food packaging applications

Keywords:

blend films , synergism , miscibility , water vapour permeability , film microstructure