Green-synthesized ZnO and ZnO-MgO nanoparticles from Abelmoschus esculentus extract for multifunctional sago starch active packaging films.

This study developed multifunctional sago starch active packaging films incorporating Abelmoschus esculentus extract (AE), green-synthesized ZnO nanoparticles (ZnONPs), and ZnO-MgO nanoparticles (ZnO-MgONPs). XRD confirmed the successful formation of crystalline nanoparticles, with average crystallite sizes of 22.4 ± 2.1 nm for ZnONPs and 18.7 ± 1.8 nm for ZnO-MgONPs. FESEM/TEM showed quasi-spherical nanoparticles with sizes of 25-35 nm and 20-30 nm, respectively. Compared with the AE-only film, the addition of ZnONPs and ZnO-MgONPs significantly improved film performance: tensile strength increased from 1.43 MPa to 2.12 MPa and 2.79 MPa, respectively, while elongation at break decreased from 60.39% to 46.12% and 32.33%. AE increased film moisture content from 6.98% to 8.78%, whereas nanoparticle incorporation improved barrier and structural properties. FTIR, XRD, FESEM, TGA, and UV-vis analyses confirmed good compatibility among the components, enhanced thermal stability, and stronger UV-shielding behavior in nanocomposite films, especially in the ZnO-MgO-containing system. The incorporation of AE enhanced the DPPH radical-scavenging activity of the films, indicating the contribution of AE-derived bioactive compounds to their antioxidant functionality. The nanocomposite films retained appreciable antioxidant activity while exhibiting improved mechanical, barrier, and antimicrobial properties. The films also exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus, indicating their potential for active food packaging applications. Overall, the AE/ZnO-MgONPs film showed the best balance of mechanical strength, thermal stability, barrier performance, and antimicrobial function, making it a promising eco-friendly packaging material.