Physical, mechanical, barrier, and thermal properties of polyol-plasticized biodegradable edible film made from kefiran

The feasibility of using kefiran as a new film-forming material was studied. Edible kefiran films were produced using glycerol and sorbitol as plasticizers at the ratio of 10, 15, and 25% (w/w) by the casting method. Physical, mechanical and water vapor permeability (WVP) properties were determined as a function of plasticizer concentration. Dynamic mechanical thermal analysis was used to determine the glass transition temperature. Increased glycerol concentration caused an increase in flexibility and WVP, as expected. However, the plasticizing effect of glycerol became less significant, particularly for puncture deformation and tensile strength. Glycerol was found to be a more suitable plasticizer for kefiran films than sorbitol. The properties of the films were related to their microstructure, which was observed by scanning electron microscopy. It was determined that plasticizers can play an important role in adapting the properties of these films to make them more suitable for food technology applications. (C) 2010 Elsevier Ltd. All rights reserved.