Development and characterization of Plantago major L. seeds mucilage - polyvinyl alcohol nano-biocomposite films incorporating Satureja sahendica Bornm. essential oil nanoemulsion and zinc oxide nanoparticles.

Nano-biocomposite films of Plantago major L. seeds mucilage (PMSM) - polyvinyl alcohol (PVA) containing Satureja sahendica Bornm. essential oil nanoemulsion (SSEO-NE), zinc oxide nanoparticles (ZnONPs), and their combination were produced and characterized. Main compounds of SSEO-NE were thymol (49.23 %), p-cymene (20.12 %), and γ-terpinene (15.23 %). Although SSEO-NE lowered ultimate tensile strength (UTS) of films (6.45 MPa), ZnONPs (9.12 MPa) and SSEO-NE - ZnONPs (8.48 MPa) intensified UTS compared to control (7.54 MPa). Adding fillers individually and in combination increased thickness (from 0.075 to 0.088 mm), increased contact angle (from 50.49 to 68.50°), reduced water vapor permeability (WVP) (from 6.66 × 10-7 to 4.55 × 10-7 g·m/m2·Pa·h), decreased light transmittance, changed swelling degree, Young's modulus, color parameters, crystallinity index, increased antibacterial characteristics against Staphylococcus aureus (reductions >6 log CFU/cm2) and Escherichia coli (reductions >6 log CFU/cm2), and enhanced antifungal properties for bread preservation during storage. Development of hydrogen bonds was specified in films containing SSEO-NE and SSEO-NE - ZnONPs. Although SSEO-NE reduced storage modulus and glass transition temperature (Tg), ZnONPs and SSEO-NE - ZnONPs increased storage modulus and Tg compared to control. Surface and cross-sectional morphology revealed different changes in film microstructures. Crystalline shape of nanoparticles was preserved in samples containing ZnONPs and SSEO-NE - ZnONPs.