Preparation and characterization of blended edible films manufactured using gelatin, tragacanth gum and, Persian gum

Composite films were produced of gelatin (G), tragacanth gum (TG) and Persian gum (PG) by using a simplex centroid design and some of their physical and mechanical properties were evaluated. The interactions between ingredients showed quadratic effects on Thickness, MC, swelling, WVTR, YM, TS, and EB while it was special cubic for WVP. The results showed that the presence of TG in blended films reduced the thickness and WVP of the films while the swelling and MC increased. Tensile strength and elongation at break of blended films significantly improved by the addition of G and the highest elongation at break observed for PG containing films. G and PG films exhibited a more homogenous structure but the presence of TG increased the irregularity of films. It can be concluded that novel edible films with new physical properties can be produced from blends of G, TG and PG and the most desirable composite film in term of physical and mechanical characteristics can be produced from the combination of G:TG:PG = 0.57:0.30:0.13.