Green Synthesis and Antibacterial Properties of Native and Pregelatinized Bitter Yam Starch‐Zinc Oxide Nanoparticles and Their Oral Dissolving Films

ABSTRACT Starches have gained attention for the green synthesis of zinc oxide nanoparticles (ZnO NPs) as reducing and capping agents. This study investigates the potential of native and pregelatinized starches of bitter yam in the green synthesis of ZnO NPs. Two methods—full green synthesis (FGS) and partial green synthesis (PGS) —were employed to produce ZnO NPs that were characterized by UV‐visible spectrophotometry, atomic absorption spectroscopy, FT‐IR, XRD, DSC, and antibacterial assays. The ZnO NPs synthesized through FGS had smaller particle sizes, and XRD spectra showed identical diffraction peaks characteristic of the wurtzite structure at 26.8°, 31.9°, 34.6°, and 36.4°. Major UV absorption peaks were observed at ∼300 nm. The FTIR spectra of the FGS nanoparticles were different from those of PGS, with major peaks around 3300–3400, 2800–3000, 1000–1200, and 400–600 cm −1 . The pregelatinized starch‐ZnO NPs synthesized via FGS showed higher antibacterial activities, with MIC and MBC values as low as 2.5 and 1.25 mg/mL, respectively. Nanoparticle‐loaded oral dissolving films also demonstrated antibacterial activities against Pseudomonas aeruginosa , Staphylococcus aureus , and Escherichia coli , supporting their potential use for oral antibacterial applications. Pregelatinized and native bitter yam starches are adequate reducing and capping biomaterials for the green synthesis of ZnO NPs.