Active Edible Film Based on Chitosan/Gelatin Incorporated with Protein Hydrolysate from Fish Processing Waste and Its Application for Shelf Life Extension of Sun-Dried Snakeskin Gourami (Trichogaster pectoralis)

Large volumes of waste by-products are generated by the continuing growth of the fish production industry. To address this issue, this study valorized the protein hydrolysate extracted from fish waste for use as an active compound in a packaging system. An edible film was developed based on a chitosan/gelatin (CG) matrix, incorporated with fish protein hydrolysate (FPH) extracted from snakeskin gourami processing waste, at concentrations of 0%, 2%, 4%, 6%, and 8%. Introducing FPH into the film’s matrix enhanced the UV protection properties but decreased transparency. The incorporation of 4% FPH significantly increased the film tensile strength and antioxidant capacity by 47.67% and 65.04%, respectively, compared to the control, while concentrations of FPH exceeding 4% had a detrimental effect on film mechanical and antioxidant capacities. 4P-CG was identified as the optimal formulation and applied as an edible coating for sun-dried snakeskin gourami at 4 °C for 14 days. The 4P-CG coating preserved the quality of sun-dried fish by reducing weight loss and inhibiting microbial growth, which extended the shelf life by four days compared to the control (non-coated) and other CG-coated fish. These findings suggest that 4P-CG is a promising, sustainable active packaging solution for enhancing the stability and safety of fatty aquatic related products while contributing to the circular economy through waste reduction.