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ePaper created 2016-03-17, 15:06:18 | version 1.45.01
72 1 Egg shells as a cause of Salmonella infections Eggs are used as a source of protein for human nutrition worldwide. Average annual consumption is 215 eggs per person, but varies quite strongly from country to country. According to the World Health Organization (WHO), Salmo- nella infections afflict more than , people in uropean countries annually The number of those afflicted no doubt has been declining the past years due to various measures. However, illness from Salmonella in Europe overall remains the second most common communicable animal-borne disease [2]. Poultry farms are the cause of Salmonella outbreaks in many cases. Undetected Salmonella infections occur in nearly 30 percent of German laying hen operations according to the German Federal Institute for Risk Assessment (BfR) [3]. Con- sumption of meat or eggs can result in its spread among the population and lead to infections. Salmonellosis is one of the diseases that must be reported. Need for disinfection techniques Current European legislation prohibits all hygienic treatment of foodstuffs, such as chemical disinfection or ionizing radia- tion, with the exception of ultraviolet radiation (UV). Conven- tional UV lamps contain many times the environmentally safe level of mercury and require longer exposure times. Most egg producers do not use the technology though, because the hygienic effectiveness is low and the maintenance costs high. The objective of the EU-funded project named OVOSHINE is to develop a cost-effective, safe, and fast physical method for disinfecting eggs in order to reduce the number of cases of illness caused by either raw eggs or insufficiently heated food- stuffs containing eggs, and increase food safety and security. New excimer lamps for UV treatment UV treatment of surfaces has long been known as a process for minimizing the number of organisms able to divide and multiply. Specialized excimer plasma lamps were designed at Fraunhofer IGB and their radiant output vs. distance, spectral distribution, and electrical power consumption tested in the lab for selected specimens. The inactivation effect of the radiation was checked for several species of bacteria using microbiological techniques. In addition, novel UVC LEDs were employed for emitting light at wavelengths considerably below 300 nm. Inactivation of vegetative cells Excimer lamps and LEDs with different wavelengths (172 nm, 222 nm, 282 nm, 285 nm, and 308 nm) were investigated. The objective was to reduce the bacterial cell count by a reduction factor1 of at least RF = 4 in just 2–10 seconds, indicating a reduction of cell counts by a factor of 105 . Reduc- tion factors of at least RF = 6 within 10 seconds could be demonstrated for vegetative cells in a test system generating reproducible irradiation at various wavelengths and radiation intensities. A reduction factor of RF = 4 was attained without problem for two-second irradiation durations. These values are in reference to investigations using strains of Escherichia coli and Salmonella enteritidis that play a role in contamina- tion of eggs. Inactivation of endospores In addition, it was also useful to investigate the extent to which endospores of Bacillus strains could be inactivated using this process, despite the relatively short treatment durations. Although forms of endospores with relatively high natural SAFE FOODSTUFFS THROUGH PHYSICAL DISINFECTION Michael Haupt, Bentsian Elkin, Sylvia Schmidt, Iris Trick, Christian Oehr MEDICINE