GAS AND WATER-VAPOR BARRIER PROPERTIES OF EDIBLE FILMS FROM PROTEIN AND CELLULOSIC MATERIALS

Edible films were made from proteins (corn-zein and wheat gluten) and celluloses (methyl cellulose and hydroxypropyl cellulose), and tested for permeability of gases. Oxygen and carbon dioxide permeabilties of edible films were generally lower than those of plastic films. However, water vapor permeabilities of edible films were higher than those of plastic films. The concentration of plasticizer significantly affected the permeability of gases. The gas permeabilities, O2, CO2 and water vapor, of cellulose films increased as the concentration of plasticizer increased. Addition of lipid (Myvacet 7-00(TM)) in the hydroxypropyl cellulose (HPC) film decreased the gas permeability. Linear relationships were found between permeability of gases and film thickness in protein films.