Antimicrobial activity and drying potential of high intensity blue light pulses (455 nm) emitted from LEDs

Amritha Prasad; Michael Gänzle; M S Roopesh

doi:10.1016/j.foodres.2021.110601

Antimicrobial activity and drying potential of high intensity blue light pulses (455 nm) emitted from LEDs

Food Res Int. 2021 Oct:148:110601. doi: 10.1016/j.foodres.2021.110601. Epub 2021 Jul 13.

Authors

Amritha Prasad¹, Michael Gänzle², M S Roopesh³

Affiliations

¹ Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2R3, Canada.
² Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2R3, Canada; College of Bioengineering and Food Science, Hubei University of Technology, Wuhan 430086, China.
³ Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2R3, Canada. Electronic address: roopeshms@ualberta.ca.

PMID: 34507746
DOI: 10.1016/j.foodres.2021.110601

Abstract

Decontamination of low water activity (a_w) foods, like pet foods is a challenging task. Treatment using light emitting diode (LED) is an emerging decontamination method, that can induce photodynamic inactivation in bacteria. The objective of this study was to understand the effect of selected product and process parameters on the antibacterial efficacy of treatment using light pulses of 455 nm wavelength on dry powdered Salmonella and pet foods equilibrated to 0.75 a_w. The surface temperature increase, weight loss, and a_w decrease in the samples were determined after LED treatments with different doses. S. Typhimurium on pet foods showed better sensitivity to 455 nm LED treatment than the powdered S. Typhimurium. For instance, 455 nm LED treatment with 785.7 J/cm² dose produced a log reduction of 1.44 log (CFU/g) in powdered S. Typhimurium population compared to 3.22 log (CFU/g) on pet food. The LED treatment was less effective against 5-strain cocktail of Salmonella in low a_w pet foods. The treated samples showed significant reduction in weight and a_w showing the heating and drying potential of 455 nm LED treatment. Significant lipid oxidation was observed in the treated pet foods. Overall, the dose, treatment time, and sample type influenced the Salmonella inactivation efficacy of 455 nm LED treatment in low a_w conditions.

Keywords: Antibacterial efficacy; Blue light pulses; Light Emitting Diode; Lipid oxidation; Low a(w) food; Salmonella.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Colony Count, Microbial
Desiccation
Food Microbiology*
Salmonella*
Water / analysis

Substances

Water