Preparation of Antibacterial Gelatin/Chitosan Composite Film With Added <scp> <i>Litsea cubeba</i> </scp> Essential Oil and Application in Beef Preservation

ABSTRACT Bioactive packaging made from biopolymers can decrease pollution in the environment in addition to prolonging the shelf life of chilled beef. A novel composite antibacterial preservative film was prepared using gelatin (Gel)/chitosan (Ch) as the film material and Litsea cubeba essential oil (LCEO) as the antibacterial agent. Its physical properties, structure, antioxidant activity, and antibacterial performance were studied. When the ratio of gelatin to chitosan was 6:4, the film exhibited good tensile strength, flexibility, and water resistance. Adding 2% LCEO to the film material further enhanced its tensile strength and improved the composite film's hydrophobicity, antioxidant activity, and antibacterial performance. The water solubility and moisture content of the composite film were reduced to 29.73% and 14.91%, respectively, while the antioxidant activity increased to 82.86%. The composite film with 2% LCEO was applied to preserve chilled beef. Compared to the composite film without essential oils, the 10th day pH, thiobarbituric acid reactive substances (TBARS), and total viable count (TVC) decreased by 0.48, 0.34 mg MDA/kg, and 1.83 log CFU/g, respectively. This indicates that the composite film containing Litsea cubeba essential oil has an excellent preservative effect on beef, extending the shelf life of chilled beef by 6 days.