Abstract

Spectroscopies analysis indicated that kefiran contains branched hexasaccharide repeating units. Neat kefiran films, 2 and 5% w/w of glycerol, D-glucitol, D-galactitol, D-mannitol, and D-limonene were incorporated as plasticizers. Neat and plasticized kefiran films were characterized by physical, thermal, mechanical, optical, and water solubilization properties. Neat kefiran had a glass transition temperature (Tg) of -20 +/- 2 degrees C and, with the addition of plasticizers between -15 to -17 +/- 2 degrees C. The values were close to the neat kefiran, and the results could be attributed to a lower amount of plasticizer used. The solubility of the glycerol plasticized films increases by 33% and decreased with the concentration of other plasticizers in comparison with the neat kefiran. D-glucitol and D-galactitol decreased the microhardness and Young's Modulus of films around 30% and 74% respectively, obtaining more flexible kefiran films. Kefiran based films could find applications as potential materials in the food-packaging industry.