Application of Erythrosine B in Antimicrobial Photodynamic Inactivation of Shigella dysenteriae in Orange Juice

Background & Objective: Outbreaks of several diseases spread by fruit juice have been widely reported. Sterilization and pasteurization methods destroy the content of bioactive substances in fruit juice. Therefore, fruit juices must be sterilized using different techniques. This study aimed to investigate the application of photodynamic inactivation (PDI) using erythrosine B to inactivate the pathogen Shigella dysenteriae in orange juice. Methods The orange juice sample was inoculated with Shigella dysenteriae. Light-emitting diode (LED) and polychromatic green light sources were used to irradiate photosensitizer erythrosine B. Cell viability was determined using colony counter method. Duration of irradiation was evaluated for 10, 20, and 30 min, respectively. Results: The results showed that neither LED nor photosensitizer treatment alone was destructive to Shigella dysenteriae. Otherwise, a 30-min treatment with green light and erythrosine B combination reduced Shigella dysenteriae colony survival to 73.49% (vs 36.5% with a polychromatic source). Conclusion: PDI using erythrosine B can be a potential method for reducing bacterial infection in juice.