Mechanical and physical properties of pea starch edible films in the presence of glycerol

The mechanical properties and moisture sorption at relative humidity (RH) range of 11–94%, water vapor permeability (WVP), solubility in water and color of the pea starch films as a function of glycerol were examined. The results showed that increasing the concentration of plasticizer resulted in improvement of the tensile strength of the films at RH <43%, the percent elongation as well as the deformation at break at RH <84%. Increasing plasticizer content and RH also resulted in films with lower Young’s modulus, lower puncture force, but higher puncture deformation. Furthermore, increasing plasticizer content led to the films with more opaque appearance. Films prepared with 15 and 25% glycerol had lower WVP in comparison with unplasticized film. This study provides information regarding the advantageous or disadvantageous of possible application of pea starch films in food packaging industry.