LED-based light sources for decontamination of food: Modelling photosensitization-based inactivation of pathogenic bacteria

Abstract

The aim of this study was to develop modern light technology (photosensitization) for non-thermal decontamination of different surfaces including food. For this purpose a light emitting diode (LED) based light source was constructed. The highpower LEDs (mfr Seoul Semiconductors) with peak wavelength at 400 nm were mounted within the prototype of light source. Antimicrobial action of aminolevulinic acid-based photosensitization was evaluated using three pathogenic bacteria (Bacillus, Listeria, and Salmonella) usually distributed on the surface of food. Pathogen inactivation by almost 6–7 orders of magnitude was achieved by ALA-based photosensitization. We suggest mathematical description for kinetics of the bacteria number within inactivation process, which is in good agreement with experimental data. Theoretical analysis of the experimental data helps in revealing the optimal conditions for food decontamination process. Keywords: LED, photosensitization, antimicrobial action