Preparation and characterization of polyethylene/carboxymethyl chitosan/tannic acid/Ag@MOF composite films for fresh pork preservation

The short shelf life of fresh pork, primarily caused by microbial contamination and lipid oxidation, remains a challenge for the food industry. To address this, we developed a novel active packaging composite film by coating a functionalized layer of carboxymethyl chitosan/tannic acid embedded with silver-based metal–organic frameworks (CTA) onto polyethylene (PE). The resulting PE/CTA films exhibited superior tensile strength (18.16 MPa), exceptional UV adsorption capacity (>98 %), enhanced barrier properties (against oxygen, moisture), and potent antibacterial/antioxidant activities. Notably, the optimized PE/CTA-8 film effectively extended the shelf life of fresh pork by 6 days compared to pure PE, as evidenced by significantly reduced weight loss, total viable count (TVC), pH, total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) values. This work presents a promising strategy for developing high-performance food packaging materials with significant commercial potential.