Naturally, salmonellae are appearing on eggs, mostly on the shell than inside the egg. These bacteria are natural residents of the intestines of poultry which are excreted with the feces. In this way eggs can be contaminated very easily. Once the egg is broken these bad germs get into the inside of the egg and could cause serious health issues for human beings
The egg itself has several natural mechanisms to protect itself from bacterial colonization and multiplication. Nevertheless, while processing eggs from chicken to packaging it is very important to fulfill hygiene regulations.
UVC disinfection of eggshells - special intensive UV light can be used to disinfect the surface of the egg, to reduce the germ load by 99.9% just within a few seconds.
The UV disinfection method is effective at wavelengths from 200 nm to 300 nm. The UVC radiation emitted has a strong bactericidal effect. It is absorbed by the DNA, destroys its structure, and inactivates living cells. If the irradiance is high enough, UV disinfection is a reliable and environmentally friendly method because chemicals need not be added. Moreover, the microorganisms cannot become resistant to UV radiation.