Demirtas, BurcuKeser, BeyzaTural, SerpilGul, Latife BetulYilmaz, IlayParlak, Mahmut EkremSaricaoglu, Furkan Turker2026-02-082026-02-0820252304-8158https://doi.org/10.3390/foods14223846https://hdl.handle.net/20.500.12885/6055This study developed and characterized zein-based edible films enriched with curcumin as natural pH-sensitive indicators for monitoring fish freshness. Colorimetric films were prepared with different curcumin concentrations (1-7% wt) and evaluated for physicochemical, mechanical, optical, and antioxidant properties. Increasing curcumin content reduced water vapor permeability (0.085-0.110 gmm/m(2)hkPa), lowered water contact angles (<90 degrees), and enhanced hydrophilicity. Films exhibited high brightness, with decreased a* and increased b* values, while light transmission decreased, improving UV barrier properties. Colorimetric response (Delta E*) across pH 3-10 was more pronounced at higher curcumin levels, confirming pH-sensitivity. Antioxidant activity significantly increased with curcumin loading (up to 24.18 mol Trolox/g). Mechanical analysis revealed decreased tensile strength but improved elongation at break, bursting strength, and deformation, supported by SEM images showing more homogeneous, micro-porous structures at 7% curcumin. Zein films containing 7% (wt) curcumin (Z/CR7) were applied to gilthead sea bream (Sparus aurata) fillets stored at 4 degrees C for 13 days. Results showed lower TBARS and TVB-N values in Z/CR7 compared to the control, indicating delayed lipid oxidation and spoilage. Colorimetric changes in the films corresponded with fish freshness deterioration, providing a clear visual indicator. Microbiological results supported chemical findings, though antimicrobial effects were limited. Curcumin-enriched zein films demonstrated strong potential as intelligent, biodegradable packaging for real-time monitoring of seafood quality.eninfo:eu-repo/semantics/openAccesscurcuminzeinedible filmspH indicatorintelligent packagingfish freshnessArticle10.3390/foods142238461422WOS:0016259079000012-s2.0-10502287716241300004Q1Q1