Antimicrobial activity of Emodin in combination with visible light against Escherichia coli and Staphylococcus aureus: Applications for food safety technology

In order to promote the application of natural photosensitizer, the photodynamic antibacterial effect of emodin combined with visible light on Escherichia coli and Staphylococcus aureus were studied in this work. The results showed that emodin mediated photodynamic antibacterial activity was dependent on concentration, light time and pH. Confocal microscopy and scanning electron microscopy confirmed that emodin can produce reactive oxygen species to kill bacteria under visible light irradiation. After treatment with emodin and visible intermittent radiation, S. aureus inoculated on the surface of fresh-cut apples was significantly reduced to 1.5 Log CFU/mL during 5 days of storage, and the storage method had no significant effect on the weight and appearance of apples. The results indicate that photodynamic inactivation of foodborne pathogens by combining emodin with visible light is a potential food safety technology.

Automated summary

This study investigated the photodynamic antibacterial effect of combining emodin with visible light on Escherichia coli and Staphylococcus aureus. The results showed that emodin mediated photodynamic antibacterial activity was influenced by concentration, light time, and pH. Confocal microscopy and scanning electron microscopy confirmed that emodin could produce reactive oxygen species to kill bacteria under visible light irradiation. After treatment with emodin and visible intermittent radiation, the population of S. aureus on fresh-cut apples significantly decreased during 5 days of storage, without affecting the weight and appearance of the apples. These findings suggest that combining emodin with visible light as a photodynamic inactivation method has the potential to enhance food safety.