Assessing of Biowaste Whey Protein as Films for Biodegradable Electronics and Packaging Applications

Conversion and utilization of biowaste from the agriculture sector into useful value-added products have been of increasing interest in recent years. Special emphasis has been placed on the use of biowaste whey protein (WP) in packaging applications. In this study, WP from cheese production waste was investigated as potential material for developing films in combination with a synthetic water-soluble biopolymer poly(vinyl alcohol) (PVA) at WP contents ranging from 25 to 50 wt %. Morphology, structure, surface contact angle, and mechanical characteristics were evaluated to assess the relationship between blend composition and materials properties. WP content plays a significant role in determining the morphology of the films, with a high WP content leading to a less compact film. It leads to strong variations in the mechanical properties. The results of the electrical properties demonstrated that the electrical conductivity increases from 1.77 × 10–11 S/cm for neat PVA to 2.06 × 10–10 S/cm for the sample with 50 wt % WP, which is accompanied by variations in dielectric constant from 19.5 to 38 at 1 Hz, respectively. In addition, the presence of WP results in a low antibacterial activity, with the maximum bacterial growth inhibition for Staphylococcus aureus (22.2%) and Escherichia coli (11.5%) being obtained for PVA neat films. Finally, the degradation test revealed that after 146 days PVA neat reached 100% degradation in soil, while the sample with 50 wt % WP was only 47% degraded. Overall, the findings of this study contribute to advance toward the development of polymer blends from biowaste with tailorable characteristics for biodegradable electronic and packaging applications.