OICC Press Journal of Nanostructure in Chemistry 2193-8865 16 2 2026 04 30 A Comparative Study of Synergistic Effects of Biogenic Nanoparticles and Plant Extracts in Tragacanth and Carboxymethyl Tragacanth-based Edible Films for Preserving Raw Pistachios 10.57647/jnsc.2026.1602.10 EN Zohre Jafari Vafa School of Physics, Damghan University, Damghan 36716-45667, Iran Ehsan Nazarzadeh Zare School of Chemistry, Damghan University, Damghan 36716-45667, Iran Ali Najafi Department of Food Science and Technology, Da.C., Islamic Azad University, Damghan, Iran Taotao Zhao The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, 3240009, Quzhou, Zhejiang, China https://orcid.org/0009-0009-4069-7491 Journal Article 2026 04 30 Bio-based nanocomposite films were developed using poly(vinyl alcohol) (PVA) reinforced with tragacanth gum (TG) and carboxymethyl tragacanth (CMT), incorporating biogenic ZnO or CuO nanoparticles and plant-derived extracts (cinnamon or clove). A comparative evaluation of structural, surface, mechanical, and oxygen barrier properties was conducted to assess their potential for active food packaging. FESEM analysis revealed that CMT-based films possessed a more homogeneous and compact microstructure with fewer microcracks compared to TG-based films. The lower contact angle observed for CMT-containing films indicated stronger intermolecular interactions and a denser polymer network. CMT-based films demonstrate a more favorable balance between strength and elongation, resulting in improved toughness and mechanical stability, which are critical for flexible food packaging applications. Oxygen permeability measurements demonstrated that optimized CMT-based film achieved a lower oxygen transmission rate (26.80 cm³/m²·24 h·0.1 MPa) than TG-based film (27.53 cm³/m²·24 h·0.1 MPa), despite reduced thickness (70 μm versus 78 μm). Analysis of diffusion and solubility coefficients indicated that reduced oxygen solubility within the CMT matrix (2.66 × 10-10 cm3/cm2.cm.Pa) was the dominant factor governing overall permeability. The practical performance of the films was further assessed by coating raw pistachios. The optimized CMT-based film preserved the visual quality of pistachios for up to 12 days under ambient conditions without observable deterioration. These results highlight CMT-based nanocomposite films as promising sustainable materials for oxygen-sensitive food packaging applications.