Effect of emulsified oil droplets and glycerol content on the physicochemical properties of Persian gum-based edible films

This work focused on the development and characterization of relatively novel edible films from Persian gum (PG) under different concentrations of glycerol and emulsified oil droplets. At 0.3% of glycerol, PG films were highly brittle for studying their mechanical properties. Higher concentrations of glycerol increased the ductility of films. The increase of oil droplet concentrations resulted in a reduction in the tensile strength, whereas, elongation at break increased. Incorporating the emulsified oil droplets resulted in a significant reduction of water solubility, swelling ability, and water vapor permeability of films. The presence of glycerol and emulsified oil droplets within the film matrix was confirmed by FTIR spectroscopy. SEM micrographs revealed that the plasticized PG films had a uniform microstructure, while, incorporating emulsified oil droplets led to relatively rough microstructure. In conclusion, PG films containing 0.9% glycerol and 1% emulsified oil droplets had desirable properties, which can be exploited for food packaging.