Innovative chitosan: pomegranate peel extract active coatings for enhanced preservation of fish fillets

Abstract

Abstract Active packaging technologies have emerged as a promising approach to enhancing the preservation of perishable foods by inhibiting microbial contamination, delaying oxidative degradation, and extending shelf life. This study focuses on the antioxidant and antimicrobial potentials of pomegranate peel extract (PPE) and its application in chitosan-based active coatings to preserve fish fillets. PPE was characterized by high levels of total phenolics (258.79 ± 2.3 mg Gallic acid equivalent GAE/g) and flavonoids (209 ± 1.7 mg/g), with gallic acid (1.02 ± 0.39 mg/g) and catechin (0.60 ± 0.21 mg/g) identified as the major bioactive compounds. These constituents contributed to strong antioxidant activity as measured by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay and 2,2-zino-bis 3-ethylbenzothiazoline-6-sulfonic acid) ABTS (assay, exhibiting inhibitory concentration (IC50 values) of 11.75 ± 1.24 µg/mL and 3.3 ± 0.86 µg/mL, respectively. PPE also demonstrated significant antimicrobial efficacy against common foodborne pathogens, generating inhibition zones ranging from 12 to 25 mm at a concentration of 100 mg/mL, with pronounced effects against Staphylococcus aureus EMCC1351 and Klebsiella spp. When incorporated into chitosan coatings at 1% and 2% concentrations, PPE effectively reduced both lipid and protein oxidation and inhibited microbial growth in fish fillets stored at refrigeration temperature (4 ± 1 °C), maintaining microbial loads within acceptable limits for up to 15 days. These findings illustrate the potential of PPE as a sustainable, natural preservative, offering an eco-friendly solution by utilizing agro-industrial by-products to develop biodegradable active packaging materials for food preservation. This approach aligns with current trends in food safety, waste valorization, and environmental sustainability.