Development and characterization of edible films enriched withpomegranate peel extract based on pea protein-psyllium (Plantago ovata) mucilage

In this study, it was aimed to produce biobased and innovative edible films by adding pomegranate peel extract (PPE) at different rates to pea protein isolate and psyllium mucilage based film formulations. For this purpose, films named as PPE-0, PPE-0.25, PPE-0.50, PPE-1 and PPE-1.5 were prepared by containing 0, 0.25, 0.50, 1 and 1.5% (w/v) PPE, respectively, and the physicochemical, barrier, color, optical, mechanical, bioactive and structural properties of the films were investigated. The results revealed that the addition of PPE had a significant effect (P≤0.05) on the thickness, moisture content, water solubility, water vapor permeability, color, light barrier and bioactive properties of the films. However, the effect of the addition of PPE on the mechanical properties of the films was not found to be significant (P≥0.05). The thickness, moisture content, water solubility and water vapor permeability values of the films containing PPE were found to be significantly higher (P≤0.05) compared to the control film (PPE-0). In addition, a significant increase in antioxidant activity and total phenolic content of the films was detected (P≤0.05) depending on the NKE concentration. The addition of PPE caused a significant decrease in the L* value of the films (P≤0.05), and a significant increase in a*, b* and ΔE values (P≤0.05). In addition, a significant increase in the opacity value of the films (P≤0.05) was detected depending on the PPE concentration. Scanning electron microscope (SEM) images revealed that the films containing PPE had a smoother surface compared to the control film. In addition, no significant difference was observed between the FTIR spectra of the control and PPE containing films. Considering the results, these PPE-enriched pea protein-psyllium mucilage based films can be considered as an innovative alternative for biobased packaging materials. KEYWORDS: Plant seed mucilage, Biobased edible film, Legume protein, Plantago ovata, Pomegranate peel extract