This research aimed to characterize and evaluate the effect of a bio-composite film containing Satureja hortensis essential oil (SEO) and Gundelia tournefortii extract (GE) for packaging Fourfinger threadfin fillets. The base film was composed of carboxymethyl chitosan (CMCH), polyvinyl alcohol (PVA), and Dorema ammoniacum gum (G). SEO was incorporated at level of 1 %, 1.5 %, and 2.5 %, while GE was added at 2 %, 3.5 %, and 2.5 % to produce enhanced films. The films were prepared using the casting method. The physico-mechanical, microbiological, and chemical properties of fish samples stored at 4 ◦C for 15 days were investigated. The results showed that incorporating SEO and GE improved the physico-mechanical properties of the CMCH/PVA/G-based film. This led to reduced moisture retention, lower water vapor permeability, and greater tensile strength (TS), along with enhanced antimicrobial and antioxidant properties compared to the film without these additives. Adding PVA and gum to CMCH significantly increased TS by 143 %. Furthermore, their high moisture 1 % essential oil and 2 % extract resulted in an additional 8 % increase in TS, with the extract having a greater effect than the essential oil. The film containing 2.5 % SEO and 2.5 % GE demonstrated the highest antioxidant and antibacterial activity, effectively preventing spoilage of the fish fillets for 12 days. Additionally, the sensory characteristics of the packaged Fourfinger threadfin fillets were considered acceptable. These findings suggest that the CMCH/PVA/G film, when combined with 2.5 % SEO and 2.5 % GE, could serve as an innovative bio-composite active packaging material to extend the freshness of fish fillets.

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