Water Vapor Permeability of Edible Bilayer Films

Abstract

ABSTRACT Edible films composed of a water soluble, carbohydrate layer (hydroxypropyl methylcellulose) and various kinds of lipid layers were tested for resistance to water vapor permeability. Films were tested at 25°C and a relative humidity differential of 85%. Films containing solid lipids, such as beeswax, paraffin, hydrogenated palm oil or stearic acid yielded permeabilities of 0.2 g · mil · day −1 · mmHg −1 or less which is a smaller value than that for low density polyethylene.