Applying Chitosan-Based Films Enriched with Borago officinalis Extract for Active and Green Packaging of Fresh Rainbow Trout Fillets

Abstract

This study aimed to apply chitosan (CS) coating films enriched with Borago officinalis extract to preserve fresh rainbow trout fillets. Extracts of B. officinalis were prepared using ethyl acetate, ethanol, water, and an ethanol-water mixture. These extracts were incorporated into chitosan coating films at 0.5% and 1% (v/v) concentrations, and their antimicrobial activity and antioxidant abilities were investigated. CS films with borage extract in ethanol-water combination showed the highest antibacterial zone diameter (9.5 ± 2.1 mm) against Staphylococcus aureus. Based on its superior antimicrobial and antioxidant activity, the ethanol-water extract was selected for further film characterization, including moisture content, swelling degree, solubility, and color. The films were then tested for their effectiveness in preserving rainbow trout fillets stored at 7 ± 1 °C. The fish samples were divided into four groups: control, chitosan coating film, chitosan coating film with 0.5% B. officinalis extract, and chitosan coating film with 1% B. officinalis extract. Physicochemical, chemical, and microbiological analyses were conducted until fillet spoilage was observed (12 days). Results demonstrated that chitosan coating films enriched with 1% extract of B. officinalis prolonged the expiration date of the fish by six days, had significant antioxidant properties, and protected fish from discoloration. While the coating films demonstrated promising antioxidant properties and the shelf life extension of the fish samples by six days, further optimization will be required to enhance their antimicrobial effectiveness.