Investigating the Use of Ultraviolet Light Emitting Diodes (UV-LEDs) for the Inactivation of Bacteria in Powdered Food Ingredients

Authors

Laura Nyhan, Department of Biological Sciences, Munster Technological University, T12 P928 Cork, IrelandFollow
Milosz Przyjalgowski, Centre for Advanced Photonics and Process Analysis, Munster Technological University, T12 P928 CorkFollow
Liam O'Faolain, CAPPA, Cork Institute of TechnologyFollow
Máire Begley, Department of Biological Sciences, Munster Technological University, T12 P928 Cork, IrelandFollow
Michael Callanan, Department of Biological Sciences, Munster Technological University, T12 P928 Cork, IrelandFollow

ORCID

https://orcid.org/0000-0002-4545-8651

Document Type

Article

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Disciplines

Food Science | Optics | Physical Sciences and Mathematics | Physics

Publication Details

Foods, vol. 10, no. 4.

Abstract

The addition of contaminated powdered spices and seasonings to finished products which do not undergo further processing represents a significant concern for food manufacturers. To reduce the incidence of bacterial contamination, seasoning ingredients should be subjected to a decontamination process. Ultraviolet light emitting diodes (UV-LEDs) have been suggested as an alternative to UV lamps for reducing the microbial load of foods, due to their increasing efficiency, robustness and decreasing cost. In this study, we investigated the efficacy of UV-LED devices for the inactivation of four bacteria (Listeria monocytogenes, Escherichia coli, Bacillus subtilis and Salmonella Typhimurium) on a plastic surface and in four powdered seasoning ingredients (onion powder, garlic powder, cheese and onion powder and chilli powder). Surface inactivation experiments with UV mercury lamps, UVC-LEDs and UVA-LEDs emitting at wavelengths of 254 nm, 270 nm and 365 nm, respectively, revealed that treatment with UVCLEDs were comparable to, or better than those observed using the mercury lamp. Bacterial reductions in the seasoning powders with UVC-LEDs were less than in the surface inactivation experiments, but significant reductions of 0.75–3 log10 colony forming units (CFU) were obtained following longer (40 s) UVC-LED exposure times. Inactivation kinetics were generally nonlinear, and a comparison of the predictive models highlighted that microbial inactivation was dependent on the combination of powder and microorganism. This study is the first to report on the efficacy of UV-LEDs for the inactivation of several different bacterial species in a variety of powdered ingredients, highlighting the potential of the technology as an alternative to the traditional UV lamps used in the food industry

Recommended Citation

Nyhan, L.; Przyjalgowski, M.; Lewis, L.; Begley, M.; Callanan, M. Investigating the Use of Ultraviolet Light Emitting Diodes (UV-LEDs) for the Inactivation of Bacteria in Powdered Food Ingredients. Foods 2021, 10, 797. https://doi.org/10.3390/foods10040797