Novel procyanidins-loaded chitosan-graft-polyvinyl alcohol film with sustained antibacterial activity for food packaging

Active food packaging materials containing procyanidins (PC) exhibits outstanding antimicrobial activity, but PC is easy to be hydrolyzed by acid. A novel water-soluble chitosan (CS)-based copolymer was prepared to be used as a carrier to provide a pH-stable environment for loading PC. CS was copolymerized with polyvinyl alcohol (PVA) via a coupling reagent-mediated approach. The CS-graft-PVA film exhibited a desirable PC encapsulation efficiency of over 95% and excellent long-term release sustainability, which was better than the conventional CS and CS-blend-PVA films. Moreover, CS-graft-PVA film had satisfactory mechanical properties and barrier properties, as well possessed a desirable antibacterial activity and biofilm inhibition against foodborne pathogenic microbes and spoilage bacteria. The film was also applied in the salmon muscle perseveration and showed a potential ability to prevent microorganism contamination and texture deterioration in 10 days. These results suggested that the CS-graft-PVA film has an excellent promise for future food packaging applications.