PHOTODYNAMIC INACTIVATION BY 405?5 NM LIGHT EMITTING DIODE AGAINST FOODBORNE PATHOGENS ON READY-TO-EAT FOODS AND ITS ANTIBACTTERIAL MECHANISM

Abstract

To investigate a potential of 405±5 nm light emitting diode (LED) as a novel preservation technology, antibacterial effect of LED against foodborne pathogens in phosphate buffered saline (PBS) and ready-to-eat foods and its impact on food qualities were assessed at different temperatures. Its antibacterial mechanism was also elucidated by determining bacterial damages. Results showed that illumination in PBS inactivated more than 90% of all bacterial populations under refrigeration for 7.5 h, while bacterial populations on foods decreased by 84–99% at refrigeration for 48 h, but no antibacterial effect under temperature abuse and room temperature, except for Salmonella spp. on cut-mango. Illumination at refrigeration caused multi-damages to bacterial DNA, RNA, proteins, and cell wall. Moreover, illumination did not significantly impact food qualities during long-term storage. Therefore, this study proposes that 405±5 nm LED at refrigeration could be useful to control foodborne pathogens on ready-to-eat foods without deterioration in retail stores.