Fish gelatin-based edible coating enriched with garlic essential oil and NaCl salt to extend the shelf life of Pangasius fillets

Pangasius fillets spoil rapidly because of their high moisture and protein contents, creating a need for natural preservation strategies. This study developed a fish gelatin-based edible coating containing garlic essential oil (GEO) and sodium chloride (NaCl), optimized by Response Surface Methodology (RSM), and evaluated its ability to preserve Pangasius fillets stored at 8°C for 16 days. The selected formulation (0.8% (v/v) GEO and 0.12% (w/v) NaCl) showed favorable film responses, including improved transparency and antimicrobial screening activity. When applied to fillets, the coating slowed the increase in microbial load, maintained TBARS below 3 mg MDA/kg and TVB-N below 20 mg N/100 g through day 12, and helped preserve texture. Coated fillets showed a larger color difference (ΔE = 12.63 on day 16) than the uncoated control (ΔE = 5.97), indicating a formulation-dependent effect on appearance. Under the criteria used in this study, quality retention was supported to approximately day 12, compared with approximately day 7 for the uncoated control. These findings demonstrate the potential of the fish gelatin-GEO-NaCl coating as an active preservation strategy for refrigerated Pangasius fillets.