Chitosan/gelatin-based multifunctional film integrated with green tea carbon dots to extend the shelf life of pork

Abstract

A multifunctional packaging film for extending the shelf life of minced pork was developed by integrating green tea-derived carbon dots (GT-CD) into a chitosan/gelatin (Ch/Gel) polymer blend. The effects of different amounts of GT-CD on the films' antibacterial, antioxidant, and other physicochemical characteristics were investigated. The Ch/Gel film with 3 wt% GT-CD showed high antioxidant activity (99.2% for ABTS and 63.87% for DPPH) and strong antibacterial action (100% eradicating E. coli and L. monocytogenes within 3 h) without significant changes in their film characteristic such as the water vapor permeability. In addition, the prepared film showed excellent UV-blocking properties (∼90.23% of UV-A, 99.65% of UV-B). When packaged with the functional film, the pork showed reduced bacterial growth (less than 1 Log CFU/g after 24 h) and preserved the meat color even when stored at 20 °C for 24 h. The GT-CD-added Ch/Gel-based films with excellent functional properties such as antioxidant, antimicrobial, and UV-barrier properties have a strong probability for active food packaging, particularly for extending shelf life and preserving the visual quality of packaged meat.