Abstract
The purpose of this study was to compare the degree of microbial inactivation and cell damage induced by intense pulsed light (IPL) and short-wavelength ultraviolet (UVC) in Listeria monocytogenes and Escherichia coli O157:H7. The viability of the food-borne pathogens treated with IPL and UVC (254nm) decreased exponentially with treatment time. Particularly dramatic reductions in L. monocytogenes and E. coli O157:H7 were observed for IPL treatments at energy densities of 376 and 455W/m 2, with an approximately 7-log reduction for a treatment time of 60-180s. Also, a 4-log reduction of L. monocytogenes and a 5-log reduction of E. coli O157:H7 were achieved with UVC irradiation for 1200s. The types and amounts of IPL- and UVC-induced DNA damage in both microorganisms were determined and compared. DNAs from cells irradiated with either IPL or UVC accumulated double-strand breaks (DSBs), single-strand breaks, and cyclobutane pyrimidine dimers, and with a similar pattern; however, more DSBs were detected following UVC than following IPL in both types of microorganism. Transmission electron microscopy observations of IPL- and UVC-induced cell damage clearly indicate that bacterial cell structures were destroyed by IPL treatment but not by UVC treatment.
| Original language | English |
|---|---|
| Pages (from-to) | 654-659 |
| Number of pages | 6 |
| Journal | Food Control |
| Volume | 25 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jun 2012 |
Bibliographical note
Funding Information:This research was supported by an RP-Grant 2011 from Ewha Womans University , a grant ( F20800308H220000111 ) from Fisheries Specific Research & Development Program funded by Ministry of Maritime Affairs and Fisheries of Korean government , and a grant ( 10162KFDA995 ) from Korea Food & Drug Administration in 2011.
Keywords
- Cell damage
- Escherichia coli O157:H7
- Intense pulsed light (IPL)
- Listeria monocytogenes
- UVC