Water vapour permeability of edible bilayer films of wheat gluten and lipids

Various formulations and methods of fabricating edible bilayer films consisting of wheat gluten as a structural layer and a thin lipid layer as a moisture barrier were investigated and examined for water vapour permeability. Solid lipids such as beeswax or paraffin wax deposited in a molten state onto the base film were the most effective water vapour barriers. A film consisting of wheat gluten, glycerol and diacetyl tartaric ester of monoglyceride as one layer, and beeswax as the other yielded a water vapour permeability of 0.0048 g mm m⁻² mmHg⁻¹ 24h⁻¹, which was less than that obtained with low density polyethylene.