Polyvinyl alcohol/silk fibroin-based photodynamic antimicrobial composite film incorporated with CuBTC-PDA-TCPP for fresh pork preservation.

Fresh food is highly susceptible to contamination by various microorganisms. Alternative approaches are urgent to develop for pork preservation. Herein, we designed a polyvinyl alcohol/silk fibroin (PVA/SF) based photodynamic antimicrobial composite film doped with a copper-based metal organic framework (MOF) material incorporating porphyrin for the preservation of chilled pork. 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) was fixed on the surface of Copper(II) benzene-1,3,5-tricarboxylate (CuBTC) with polydopamine (PDA) as the intermediate layer to obtain CuBTC-PDA-TCPP. Then, CuBTC-PDA-TCPP was loaded into PVA/SF matrix to prepare the PVA/SF-MOF film for packaging fresh chilled pork. The inhibition rates on Escherichia coli and Staphylococcus aureus reached 99.99 % by the prepared material under photodynamic stimulation. The bacterial inhibition rate of PVA/SF-MOF film packaging was 79.6 %, showing good preservation and antimicrobial effect. Importantly, the films had low cytotoxicity and low possibility of Cu2+migration into pork. This work proposed a promising strategy for the development of light-activated smart antimicrobial food packaging.