Water vapour and CO(2) transmissions of methyl cellulose (MC)-based edible films with varying amounts of the fatty acids, stearic acid (SA), palmitic acid (PA) and lauric acid (LA) were studied and the results were compared with those obtained for a film without added fatty acid. Water vapour transmission rate (WVTR), water vapour permeance (WVPN) and water vapour permeability (WVP) values of films were determined by measuring the amounts of water vapour transmitted through the film and then adsorbed on anhydrous CaCl(2) as a function of time, using a static method. A recently-developed static method which utilises ascarite to adsorb carbon dioxide transmitted through the film was employed for the determination of carbon dioxide transmission rate (CO(2)TR), carbon dioxide permeance (CO(2)PN) and carbon dioxide permeability (CO(2)P) of films. Among the three fatty acids studied, SA was found to be the most effective in decreasing both the water vapour and the CO(2) transmissions of films. In general, it was observed that WVTR, WVPN and WVP values of films decreased with increasing fatty acid content in the film composition. CO(2) transmission parameters also decreased with increasing SA and PA contents but increased with increasing LA content of films. (C) 2001 Elsevier Science Ltd. All rights reserved.
Water vapour and CO 2 transmissions of methyl cellulose (MC)-based edible ?lms with varying amounts of the fatty acids, stearic acid (SA), palmitic acid (PA) and lauric acid (LA) were studied and the results were compared with those obtained for a ?lm without added fatty acid. Water vapour transmission rate (WVTR), water vapour permeance (WVPN) and water vapour permeability (WVP) values of ?lms were determined by measuring the amounts of water vapour transmitted through the ?lm and then adsorbed on anhydrous CaCl 2 as a function of time, using a static method. A recently-developed static method which utilises ascarite to adsorb carbon dioxide transmitted through the ?lm was employed for the determination of carbon dioxide transmission rate (CO 2 TR), carbon dioxide permeance (CO 2 PN) and carbon dioxide permeability (CO 2 P) of ?lms. Among the three fatty acids studied, SA was found to be the most e?ective in decreasing both the water vapour and the CO 2 transmissions of ?lms. In general, it was observed that WVTR, WVPN and WVP values of ?lms decreased with increasing fatty acid content in the ?lm composition. CO 2 transmission parameters also decreased with increasing SA and PA contents but increased with increasing LA content of ?lms.
