Citrus peel extract–enriched gelatin edible films as natural preservatives to enhance the shelf life and quality of chicken burgers

Abstract This study examines the effects of edible gelatin films enriched with citrus fruit peel extracts (grapefruit, orange, and lemon) at concentrations of 1%, 2%, and 4% on the quality and shelf life of chicken burgers during frozen storage at − 18 °C, over 147 days. Significantly, the duration of shelf life was increased by inhibiting two factors, microbial and oxidation, in chicken burgers by using enriched gelatin films. On day 147, 4% grapefruit peel extract showed significantly lower peroxide value (4.50 meq O₂/kg), thiobarbituric acid value (0.74 mg MDA/kg), total volatile basic nitrogen (11.20 mg N/100 g), and pH (6.77) than the unwrapped control samples ( p ≤ 0.05). Moreover, microbial analysis revealed that 4% citrus fruit peel extracts significantly inhibited the burgers’ total aerobic psychrophilic count, total mesophilic bacteria, total coliform bacteria, total lactic acid bacteria, total yeast and mold count compared with the control and other groups. Grapefruit peel exhibited the highest antioxidant and phenolic content, followed by orange and lemon peels. Overall, gelatin films fortified with citrus peel extracts 4% showed improved an-tioxidant and antibacterial capabilities, indicating their potential as natural active packaging materials for meat preservation.