Characterization of edible gum cordia film: Effects of beeswax

• Water vapor barrier property of gum cordia film was improved via beeswax addition.
• Beeswax increased the oxygen permeability by a factor of about 50.
• Level of beeswax affected mechanical properties of gum cordia film.
• Beeswax formed stable emulsion with gum cordia.

In order to expand the applications of gum cordia films, beeswax was added into the gum and properties of resulting films were studied. Film forming emulsions were prepared by gum cordia, polyethylene glycol 400, beeswax (0.05–0.20 g g−1 of gum cordia) and glycerol monostearate. The emulsions were stable during film preparation process. Lipid droplets were found to be homogenously disperse into gum cordia with the average size of about 1.3 μm. Films were prepared by emulsion casting method. Addition of beeswax reduced tensile strength, Young's modulus and elongation at break of the films. Water vapor permeability (WVP) of beeswax containing films was 0.06–0.33 × 10−10 g m−1 s−1 Pa−1 which is about one magnitude less than the films without wax. The activation energy of WVP was found to be higher (15–18 kJ mol−1) for the films incorporated with beeswax than of beeswax free film (6.6 kJ mol−1). We also observed that addition of beeswax at the concentration of 0.05 g g−1 increased oxygen permeability (OP) by a factor of about 50 (from 0.39 to 18.73 g m−1 s−1 Pa−1). However, further increase in beeswax did not increase the OP.