Development of edible blend films with good mechanical and barrier properties from pea starch and guar gum

The individual and interactive impacts of guar gum and glycerol on the pea-starch-based edible film characteristics were examined using three factors with three-level Box–Behnken response surface design (BBD). The results showed that density and elongation at break were only significantly (p < 0.05) affected by pea starch and guar gum in a positive linear fashion. The quadratic regression coefficient of pea starch showed a significant effect (p < 0.05) on thickness, density, puncture force, water vapor permeability, and tensile strength, while tensile strength and Young's modulus were affected by the quadratic regression coefficient of glycerol and guar gum, respectively. The results were analyzed using Pareto analysis of variance (ANOVA) and the developed predictive equations for each response variable presented reliable and satisfactory fit with high coefficient of determination (R ²) values (≥0.96). The optimized conditions with the goal of maximizing mechanical properties and minimizing water vapor permeability were 2.5 g pea starch, 0.3 g guar gum, and 25% w/w glycerol based on the dry film matter in 100 mL of distilled water.