Mechanical properties of gellan and gelatin composite films

The effect of gellan to gelatin ratio and NaCl concentration on the mechanical properties of gellan/gelatin composite films were studied using a Texture Analyzer. Tensile strength (TS) of the composite films linearly decreased as the gelatin ratio increased, whereas the tensile elongation (TE) increased with increasing gelatin proportion. TS and TE were also significantly affected by the NaCl concentration. TS decreased with increasing NaCl concentration for gellan film, whereas TS showed the maximum values at NaCl concentration of 50 mM for the other composite films. Water solubility and swelling ratio decreased with increasing gelatin proportion up to 40%. These results suggest that modifying the ratio of gellan and gelatin improves the mechanical properties of the composite film. These films appears to have potential as packing and/or coating materials, replacing synthetic polymer films.