Preparation and characterization of tragacanth–locust bean gum edible blend films

• A new blend film has been made from binary solutions of GT and LBG.
• A distinct synergism between GT and LBG was observed.
• The surface tensions of gum solutions were lowered significantly (p < 0.05) after blending together.
• The transparency, water vapour barrier and mechanical properties of films were improved by incorporating LBG in blend.
• GT–LBG blend film has the potential to be used as a new packaging material.

The present work introduces the structure and physicomechanical properties of a novel blend film made from binary solutions of gum tragacanth (GT) and locust bean gum (LBG) at different mixing ratios. Apparent viscosities and surface tensions of individual and blend gum solutions were also investigated. The viscosity data indicated that there was a distinct synergism between the two gums at all mixing ratios. FTIR spectra showed the existence of noncovalent intermolecular interactions between gums. The surface tensions of binary solutions were significantly lower than those of individual gums which is advantageous for coating applications. All films had homogenous and smooth surface morphology and their transparency, water vapour barrier and mechanical properties were improved by incorporating LBG in blend. The results of this study suggest that GT–LBG blend film, owing to its desirable properties, has the potential to be used as a new degradable food packaging material.