Publication Database

Efficacy of UV-C irradiation emitted by mercury vapor lamp and LED on the bacterial load of eggshells (2021)

Art

Poster

Autoren

Opherden, S. (WE 8)

Fleischmann, S. (WE 8)

Alter, T. (WE 8)

Robé, C. (WE 10)

Szabo, I.

Hadziabdic, S.

Gensch, A.

Rotsch, P.

Wiese, G.

Roesler, U. (WE 10)

Forschungsprojekt

Einsatz von UV/UV-LED-Strahlung zur Reduktion von Mikroorganismen auf Eiern (UVegg)

Kongress

Advanced UV for Life and the IUVA Confernece ICULTA 2021

online, 19. – 20.04.2021

Quelle

ICULTA 2021. The 2nd International Conference on UV LED Technologies & Applications April 19 – 20, 2021

— S. 88

Sprache

Englisch

Verweise

URL (Volltext): https://www.iculta.com/program

Kontakt

Institut für Tier- und Umwelthygiene

Robert-von-Ostertag-Str. 7-13
14169 Berlin
+49 30 838 51845
tierhygiene@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Contamination with zoonotic pathogens is one of the main problems in food production. A specific challenge is the supply of eggs free of pathogenic bacteria. In German packing centers, it is not permitted to wash eggs nor to treat them with chemical substances. Internationally, some companies use ultraviolet-C (UV-C) light-emitting mercury vapor lamps for bacterial decontamination. An alternative approach is the application of UV-C LEDs. They are associated with various ecological and economic advantages.
The objective of this study is the evaluation of UV-C LED irradiation compared to mercury vapor lamps for bacterial decontamination of eggshells.
For laboratory testing, the following gram-positive and gram-negative bacteria were selected, according to the consumer’s health risk:
> non-ESBL- and ESBL-producing Escherichia coli
> Methicillin-resistant Staphylococcus aureus
> Enterococcus faecium
> Campylobacter jejuni
> Salmonella Enteritidis and Typhimurium.
Egg surfaces were inoculated with a defined bacterial number. An organic load was added to simulate practical conditions. Afterward, the surface was sampled with a cotton swab. The bacterial count was estimated with and without UV-C treatment. The LED set-up consisted of a panel of diodes with a maximum spectral density at 280 nm and an irradiance of ~ 2.4 mW/cm2. In contrast, the experimental arrangement of vapor lamps resulted in an irradiance of ~ 5.0 mW/cm2. Each treatment was performed for 5 seconds while the egg is rolling on a conveyer.
Recovery rates varied for individual bacterial species. Conventional treatment with mercury lamps resulted in up to 3 log10 reductions. Treatment with LED achieved up to 1.5 log10 reductions. Additional organic load on the eggshell diminished the efficacy of both UV-C sources.
In this study, the swab technique was verified as a convenient sampling method for eggshells. If both UV-C sources achieved same intensity levels, LEDs should be seen as the better choice for egg packaging centers due to their favorable properties.