Morphology and water vapor permeability of emulsion films based on mesquite gum

The potential of mesquite gum as structural agent in the formulation of emulsion films was studied. Two hydrophobic blends with a hydrophilic-lipophilic balance of 6.0 at different concentrations were used as the dispersed phase. The water vapor permeability of the emulsion films was determined under different water vapor partial gradients and temperatures. Results showed that emulsion droplet size was affected by the chemical nature of the hydrophobic blend. In turn, film morphology, water vapor permeability and activation energy were influenced by emulsion droplet size and distribution. Water vapor permeability for the films made with dispersed phases of 20% (w/w) sorbitan monostearate-gelatin and of 20% (w/w) sorbitan monostearate-polyoxyethylene derivative of sorbitan monooleate blends ranged from 87 to 160 (g.mm/kPa.d.m(2)) for the former and from 56 to 84 (g.mm/kPa.d.m(2)) for the latter, in a range of water vapor partial gradients from 92-86% to 92-53%. Mesquite gum may be considered as a suitable structural support for preparing emulsion films.