Propiedades nanomecánicas en películas comestibles de almidón de plátano-goma gelana

The use of new materials for produce edible films has grown in recent years but, these new materials must have good barrier properties and acceptable mechanical characteristics (flexible and stretchable structure) for an easy application. In food packaging materials, mechanical and barrier properties are the main criteria for selection them. Therefore, the target was to study the effects of composition on hardness properties and elastic modulus using nanoindentation atomic force microscopy. Three-factor Box-Behnken design at three levels was employed to evaluate the effect of gellan gum-banana starch (0.25-0.75%) and glycerol (1- 3%) concentration on mechanical properties. Edible films exhibited roughness values between 35.2 and 110.8 nm and hardness values between 0.8979 and 3.0777 MPa. Elastic modulus was 0.0473 to 0.2687 GPa, these values allow suggest that have soft, flexible edible films from blends of rubber banana starch and gellan gum. Hardness and elastic module properties of edible films of banana starch-gellan gum were influenced by the glycerol concentration; this concentration was inversely proportional to the hardness and elastic module. The lowest roughness values were obtained with 0.5% gellan gum, 0.5% starch and 2% glycerol.