Photoinduced Antimicrobial Activity of Curcumin-Containing Coatings: Molecular Interaction, Stability and Potential Application in Food Decontamination

[Image: see text] Polyvinyl acetate (PVAc) and curcumin (Cu) were utilized for preparing new protecting PVAc–Cu(x) (x = 1, 5 and 10) coatings exerting antimicrobial photodynamic activity upon white light irradiation. Toward Salmonella typhimurium or Staphylococcus aureus, the killing efficiency represented the dependence on the Cu concentration and irradiation intensity. Toward S. aureus, the killing efficiency of PVAc–Cu(10) coating reached 93% at an energy density of 72 J/cm(2). With the change in storage time of coating, the results implied significant stability of photosterilization efficiency within 60 days. Compared with the control experiment, lower total viable counts (TVCs) and total volatile basic nitrogen (TVB-N) values in fresh meat packaged by PVDC films with PVAc–Cu(10) coatings during storage at 4 °C demonstrated the practicability of the PVAc–Cu(x) coatings in decontaminating fresh pork. PVAc packed curcumin tightly within polymer chains, thus preventing tautomerization or, more probably, conformational transition, which is advantageous for improving photostability and emission lifetime.