Development and characterization of active edible films based on Pangasius sp. skin gelatin and carrageenan enriched with avocado peel essential oil

Growing environmental concerns have led to the development of biodegradable alternatives to synthetic polymers. Edible films for food packaging can be formulated from various biopolymers, including gelatin, which is known for its excellent film-forming properties but exhibits poor water vapor resistance. Incorporating κ-carrageenan may enhance the mechanical properties of gelatin films, while avocado peel essential oil could provide antioxidant and antimicrobial functionalities, improving the overall quality of the packaging material. This study aimed to develop and characterize gelatin-based edible films derived from catfish (Pangasius sp.) skin, incorporating κ-carrageenan and avocado peel essential oil. The research involved gelatin extraction, film formulation, and evaluation of physicochemical properties. The extracted gelatin had a moisture content of 9.74%, an ash content of 0.55%, a pH of 5.81, and a viscosity of 19 mPas, meeting the SNI 8622:2018 standards. GC-MS analysis identified 22 compounds in the avocado peel essential oil, predominantly terpenoids. The essential oil exhibited antibacterial activity against Staphylococcus aureus (12.70 ± 0.38 mm) and Escherichia coli (5.94 ± 0.13 mm) and demonstrated potent antioxidant activity with an IC₅₀ value of 7.58 mg/l. Incorporating avocado peel essential oil affected the physical properties of the gelatin carrageenan films, decreasing tensile strength, water vapor transmission rate, and brightness index, while increasing elongation at break, film thickness, yellow index, and clarity index. These findings suggest that gelatin-based films enriched with κ-carrageenan and avocado peel essential oil have potential as biodegradable active packaging materials.