Fabrication and comparison of active films from chitosan incorporating different spice extracts for shelf life extension of refrigerated pork

In this study, six novel chitosan-based films incorporated with spice extracts (thyme, cloves, prickly ash, fennel, geranium and cinnamon) were fabricated to prolong the shelf life of refrigerated pork. Adding the spice extracts to chitosan-based films significantly improved the physical property, such as thickness, density, swelling, moisture content, color parameters, and light transmittance. These changes were verified via the observation of SEM. FTIR, XRD and TGA spectra indicated that the improvement in the characteristics of the composite films could be attributed to the intermolecular interaction between the chitosan and the different spice extracts. Furthermore, the antioxidant and antibacterial properties of the composite films were measured and analyzed, indicating a distinct ability to scavenge DPPH radicals, while exhibiting a prominent inhibitory effect against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Finally, fresh pork coated with different chitosan film-forming solutions was prepared for a preservation study. All samples were stored at 4 degrees C for 7 d, after which the pH values, color values and total viable count (TVC) of the bacteria were compared. All the composite coatings, especially those containing cloves, fennels, and geranium, displayed an excellent ability to enhance the preservation of refrigerated pork. In summary, the incorporation of spice extracts in chitosan-based films exhibited substantial potential for utilization in food preservation.

Automated summary

This study fabricated chitosan-based films incorporated with various spice extracts, which significantly improved their physical properties and antioxidant, antibacterial activities. Cloves, fennel, and geranium exhibited excellent abilities to enhance the preservation of refrigerated pork. The incorporation of spice extracts in chitosan-based films showed substantial potential for utilization in food preservation.