| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 6393632 | Food Control | 2012 | 6 Pages |
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 (254 nm) 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 455 W/m2, with an approximately 7-log reduction for a treatment time of 60-180 s. Also, a 4-log reduction of L. monocytogenes and a 5-log reduction of E. coli O157:H7 were achieved with UVC irradiation for 1200 s. 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.
⺠Cell damage induced by intense pulsed light (IPL) and UVC irradiation were compared. ⺠The viability of pathogens decreased exponentially with IPL treatment time. ⺠More double-strand breaks accumulated in DNA from bacteria treated with IPL than UVC. ⺠Bacterial cell structures were destroyed by IPL treatment but not by UVC treatment.
