This study examined the feasibility of using kefiran, an exopolysaccharide obtained from kefir grains, as a
new film-forming material. Kefiran-based films, with and without glycerol as plasticizer, were prepared
by a casting and solvent-evaporation method. To study the impact of the incorporation of glycerol into
the film matrix, physical, mechanical, and thermal properties of the films were investigated. As expected,
the increase of glycerol concentration from 15% to 35% w/w increased extensibility but decreased tensile
strength, implying higher mobility of polymer chains by the plasticizing effect of glycerol. Water vapour
permeability of films was found to increase as the plasticizer content increased. Glass transition temperatures
decreased as a result of plasticization as glycerol content increased. The properties of the films
were related to their microstructure, which was observed by scanning electron microscopy. Thus, it
was observed that plasticizer is a significant factor in the properties of these films and their food technology
applications.