In Japan, chicken eggs are eaten without being heated, and there are reports of salmonella tests.
Results) Eggs are safe for about 6 weeks even at 10℃ or 20℃.
In both tests, SE bacteria was forcibly inoculated into the egg white near the yolk, where it normally does not occur, and the storage temperature was varied to examine the growth of the bacteria.
In an experiment at Kitasato University, eggs were stored at 10°C, 20°C, and 30°C, and SE bacteria did not grow even after 6 weeks when eggs were stored at 10°C and 20°C. After 4 weeks, the number of viable bacteria actually decreased. After storage at 10°C for 5 weeks and 20°C for 3 weeks, one SE bacterium grew, which may be due to damage to the vitelline membrane during inoculation. Based on this result, ``it is thought that there is no problem with safety if stored at 10℃.''
In tests conducted by the Livestock Safety and Health Research Institute, the growth status of SE was investigated at storage temperatures of 20°C, 25°C, and 30°C. In study 2, no development was observed until after 4 weeks (although abnormal eggs with bacterial growth after 5 and 6 weeks may have been inoculated with SE near the vitelline membrane). At 25°C and 30°C, an increase in bacterial numbers was observed after 3 weeks.
The institute said, ``The results suggest that it is appropriate to store eggs at temperatures below 20 degrees Celsius for up to six weeks,'' and that no problems will occur within this period.