Application of Oregano Essential Oil-Based Antibacterial Film in the Preservation of Fresh Ningxia Tan Sheep Meat

In order to solve the problem of quality deterioration in Ningxia Tan sheep meat caused by microbial growth during long-distance transportation, an antibacterial film, GEL/KT-OEO, was prepared by the solution casting method with oregano essential oil (OEO) as the antibacterial agent and keratin (KT) and gelatin (GEL) as the film-forming matrices. Its microstructure, chemical groups, crystal structure and thermal properties were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The effect of GEL/KT-OEO on the quality preservation of Ningxia Tan sheep meat was evaluated during storage at 4 ℃. The results showed that the film with 10% OEO exhibited optimal physical and bacteriostatic properties, with light transmittance, tensile strength, elongation at break, moisture content (MC), water solubility (WS), inhibition rates against Escherichia coli and Staphylococcus aureus of (36.20 ± 0.31)%, (0.58 ± 0.06) MPa, (82.53 ± 2.73)%, (14.31 ± 0.49)%, (48.98 ± 0.69)%, (97.28 ± 1.34)% and (99.67 ± 0.33)%, respectively. The addition of OEO did not change the molecular structure or functional groups of the antibacterial film, but reduced its crystallinity and improved its thermal stability. The antibacterial film with 10% OEO resulted in superior sensory characteristics, pH, total volatile basic nitrogen (TVB-N) value and thiobarbituric acid reactive substance (TBARS) value of lamb meat stored at 4 ℃ when compared with the blank group and polyethylene (PE) film (P < 0.05), prolonging the shelf life from 5 to 7 days relative to the PE film group. The GEL/KT-OEO antibacterial film shows significant potential and value for application in meat preservation, which provides a new and effective solution for maintaining meat quality during long-distance transportation.