T2-01 Efficacy of Three Light Technologies for Reducing Microbial Populations

Monday, August 4, 2014: 8:30 AM
Room 203-204 (Indiana Convention Center)
Angeliki Birmpa, University of Patras, Patras, Greece
Spyros Paparrodopoulos, University of Patras, Patras, Greece
Paul Whyte, School of Veterinary Medicine, Dublin, Ireland
James Lyng, School of Agriculture and Food Science, Dublin, Ireland
Apostolos Vantarakis, University of Patras, Patras, Greece
Introduction: In recent years, non-thermal technologies have shown potential as alternative disinfection technologies. Three light technologies (e.g., High-Intensity Narrow-Spectrum (HINS) light 395 ± 5 nm, continuous UV light and High Intensity Light Pulses (HILP)) are non-thermal technologies which can be used to inactivate bacteria, yeasts, molds and even viruses.

Purpose: The purpose of the current study was to evaluate the effectiveness of three non-thermal light technologies (NUV-Vis, Continuous UV and HILP) on their ability to inactivate Escherichia coli K12 and Listeria innocua.

Methods: Experiments were conducted using E. coli K12 (DSM 1607) and L. innocua (NCTC 11288). The suspensions containing both E. coli and L. innocua were assessed for susceptibility to three light technologies in a liquid matrix (MRD). A wide spectrum of dosages, varying between 0.18-106.2 J/cm2, was used for all the light treatments.

Results: The results of the present study show that the HIPL treatment inactivated both E. coli and L. innocua more rapidly and effectively than either continuous UV-C or NUV-vis treatments. With HILP at a distance of 2.5 cm from the lamp, E. coli and L. innocua populations were reduced by 3.07 and 3.77 log CFU/ml, respectively, after a 5 sec treatment time, and were shown to be below the limit of detection (< 0.22 log CFU/ml) following 30 sec exposure to HILP (106.2 J/cm2).

Significance: These data suggest that short treatment times for decontamination efficiency would be an important factor related to productivity in the food industry. The findings presented here suggest the expansion of the aforementioned light technologies on food decontamination. Thus, these alternative non-thermal disinfection light techniques could find potential application for decontamination in the food industry.