Water vapor permeability, tensile properties and solubility of methylcellulose-based edible films

Water vapor permeability (WVP), tensile strength (TS), % elongation (E), adsorption capacity and % soluble matter (SM) were investigated in methylcellulose (MC) films plasticized by polyethylene glycol (PEG). The WVP of films was determined to be 0.232 x 10(-10)-1.160 x 10(-10) g/m s Pa, TS between 17 and 44 N/mm(2) and %E between 14% and 97%, depending on composition. Film formation was affected by MC concentration, ethanol percent in the solution and the presence of PEG. Incorporation of various molecular weight (MW) PEGs to the polymer matrix increased both WVP and %E, decreased TS. Increase in PEG400 concentration had similar effects. Solubility studies indicated that MC films were water-soluble and PEG containing samples had higher solubilities. Results suggest that mainly hydrogen bonding between PEG and MC or blocking effect in the case of high MW PEGs determine the film properties. (C) 2003 Elsevier Ltd. All rights reserved.