Novel approach to control Salmonella enterica by modern biophotonic technology: photosensitization

Aims: Salmonellosis is one of the most common foodborne diseases in the world. The aim of this study was to evaluate the antibacterial efficiency of 5‐aminolevulinic acid (ALA) based photosensitization against one of food pathogens Salmonella enterica. Methods and Results: Salmonella enterica was incubated with ALA (7·5 mmol l−1) for 1–4 h and afterwards illuminated with visible light. The light source used for illumination of S. enterica emitted light λ = 400 nm with energy density 20 mW cm−2. The illumination time varied from 0 to 20 min and subsequently a total energy dose reached 0–24 J cm−2. The data obtained indicate that S. enterica is able to produce endogenous photosensitizer PpIX when incubated with ALA. Remarkable inactivation of micro‐organisms can be achieved (6 log) after photosensitization. It is obvious that photosensitization‐based inactivation of S. enterica depends on illumination as well as incubation with ALA time. Conclusion: ALA‐based photosensitization can be an effective tool against multi‐drug resistant Gram‐negative bacteria S. enterica serovar Typhimurium. Significance and Impact of the Study: Experimental data and mathematical evaluations support the idea that ALA‐based photosensitization can be a useful tool for the development of nonthermal food preservation technology in future.