Novel Photodynamic Inactivation Strategy for Salmonella Enteritidis PT4 on Eggshells: Exploiting the Antimicrobial Potential of Curcumin and Carvacrol.

Photodynamic inactivation (PDI) is a new and promising strategy for eliminating foodborne pathogenic bacteria in food preservation, reducing associated health risks for consumers. This study aimed to develop an innovative PDI-based system to inactivate Salmonella Enteritidis PT4 on eggshells. The system includes 405 nm light-emitting diodes (LEDs) and the application of curcumin or carvacrol as photosensitizers. The antibacterial activity of the system was investigated in eggshells inoculated with S. Enteritidis PT4 at different temperatures (4, 25, and 37°C) and exposure times (15, 30, and 45 min). Carvacrol + LEDs application was completely inhibited S. Enteritdis PT4 at 4 (after 30 min), 25, and 37°C at the 45th min. Curcumin + LED completely inhibited bacterial growth after 45 min at 4 and 25°C. The results showed that simultaneous use of carvacrol or curcumin with LEDs at various temperatures exhibited significant antibacterial activity against the bacteria depending on the exposure time. The application of curcumin or carvacrol sourced via PDI in the originally developed system resulted in any significant changes in egg quality parameters and sensory properties. This study demonstrated that PDI-based system using curcumin or carvacrol as photosensitizers could be a potential tool for decontamination of eggs contaminated with S. Enteritidis PT4.