title: Using UVC Light-Emitting Diodes at Wavelengths of 266 to 279 Nanometers To Inactivate Foodborne Pathogens and Pasteurize Sliced Cheese.
abstract: UVC light is a widely used sterilization technology. However, UV lamps have several limitations, including low activity at refrigeration temperatures, a long warm-up time, and risk of mercury exposure. UV-type lamps only emit light at 254 nm, so as an alternative, UV light-emitting diodes (UV-LEDs) which can produce the desired wavelengths have been developed. In this study, we validated the inactivation efficacy of UV-LEDs by wavelength and compared the results to those of conventional UV lamps. Selective media inoculated with Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes were irradiated using UV-LEDs at 266, 270, 275, and 279 nm in the UVC spectrum at 0.1, 0.2, 0.5, and 0.7 mJ/cm(2), respectively. The radiation intensity of the UV-LEDs was about 4 μW/cm(2), and UV lamps were covered with polypropylene films to adjust the light intensity similar to those of UV-LEDs. In addition, we applied UV-LED to sliced cheese at doses of 1, 2, and 3 mJ/cm(2). Our results showed that inactivation rates after UV-LED treatment were significantly different (P < 0.05) from those of UV lamps at a similar intensity. On microbiological media, UV-LED treatments at 266 and 270 nm showed significantly different (P < 0.05) inactivation effects than other wavelength modules. For sliced cheeses, 4- to 5-log reductions occurred after treatment at 3 mJ/cm(2) for all three pathogens, with negligible generation of injured cells.
authors.affiliation: Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul, Republic of Korea, and Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, Republic of Korea.
authors.forename: Soo-Ji
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul, Republic of Korea, and Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, Republic of Korea.
authors.forename: Do-Kyun
authors.initials: DK
authors.lastname: Kim
authors.affiliation: Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul, Republic of Korea, and Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, Republic of Korea kang7820@snu.ac.kr.
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kang
mesh_terms: D002611:Cheese / Q000032:analysis / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000254:growth & development / Q000528:radiation effects*; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005514:Food Irradiation / Q000295:instrumentation / Q000379:methods*; D005516:Food Microbiology; D006358:Hot Temperature; D008089:Listeria monocytogenes / Q000254:growth & development / Q000528:radiation effects*; D050296:Microbial Viability / Q000528:radiation effects; D061352:Pasteurization; D012486:Salmonella typhimurium / Q000254:growth & development / Q000528:radiation effects*; D014466:Ultraviolet Rays