Films based on kefiran, an exopolysaccharide obtained from kefir grain: development and characterization

PIERMARIA, JUDITH;; PINOTTI, ADRIANA,; GARCIA, MARÍA A.; ABRAHAM, ANALIA G

FOOD HYDROCOLLOIDS

Elsevier

Lugar: Food Hydrocolloids (2009), doi:10.1016/j.foodhyd.2008.05.003; Año: 2009 vol. 23 p. 684 - 690

0268-005X

Kefiran, an exopolysaccharide produced by microorganisms present in the kefir grains, is a glucogalactanthat has several health promoting properties. In the present work, the ability of kefiran to form films andthe effect of glycerol addition at different concentrations on film properties was evaluated. Kefiran wasable to form films at concentrations ranging from 5 to 15 g/kg. The concentration 10 g/kg was selectedbecause the films were easily removed from the plate. All film-forming solutions exhibited a pseudoplasticbehavior; glycerol addition did not modify the solution rheological properties.Kefiran films exhibited differential solubility characteristics, at the different assayed temperatures. Thesefilms exhibited good water vapor barrier properties and the addition of 25 g of glycerol per 100 g ofpolysaccharide allowed the optimum value of 4.09  1011 g/m s Pa to be obtained.Films without glycerol were brittle and rigid since they showed high elastic modulus and tensile strengthvalues and low deformation at break. Glycerol addition led to extremely high elongation values, allowingflexibilities comparable to those of synthetic materials.