Chemical sterilisation methods are broadly used in the hatcheries because the sterilisation of eggs improves the hatchability rate. However, chemical sterilisation methods are not allowed in human consumption eggs in the European Union.
Commercial UV lamps are the only sanitation technology approved by the EC. However, this technology suffers from several problems. One of them is that the regular UV lamps are not environment friendly (They are constructed with Mercury). Other problem associated with this technology is that the entire surface of the egg has to be illuminated. Small portions of organic material can result in small shadowed areas that enable the survival of some bacteria. Furthermore, these lamps are expensive and have to be changed periodically to maintain low time sterilisation rates. Despite the fact that they are not the most efficient sterilisation methods due to the occurrence of untreated spots on the egg surface, they are the only methods allowed in the EU because they do not generate harmful contaminating residues.
The most common ionising radiation procedure involves irradiating the egg with gamma radiation usually from a Cobalt-60 source. Unlike with UV light, this method sterilises the entire egg. This technology is approved by the FDA and has been in use for almost 40 years. However, there is serious public concern over the use of this technology.
The term plasma refers to a gas which has been partially ionised. There are several ways of ionise a gas, but the most typical is applying a high electric field to the gas. In the industry, plasma is used for sterilisation, surface modification, soldering and other applications. At the moment no commercial equipment is available for the sterilisation of eggs or similar products.
A SLOW, time-consuming method.
INCREASES the number of eggs that crack during the pasteurisation process.
NON USABLE on table eggs.
THE APPLICATION OF CHEMICALS to eggs for human consumption is prohibited in the EU and can only be used on fertilised eggs destined for reproduction.
REQUIRES FULL PROTECTION of personnel during application.
ENVIRONMENTAL THREAT due to harmful residues.
NON SPECIFIC wavelength.
NON ENVIRONMENTALLY friendly.
SHORTER useful life
COMMERCIAL MERCURY LAMPS need long exposition times (minutes).
HIGH MAINTENANCE costs.
NOT POSITIVELY viewed by consumers. Producers are obliged to clearly label irradiated eggs.
INVOLVES HIGH COSTS, due to the expensive special installations required.
COMPANIES that use ionizing radiation need special permits to sterilise food.
NOT PERMITTED in the European Union.
EXPENSIVE. Since noble gases have to be used to create the plasma the cost of the sterilisation is notable.
SLOW. No online method is viable since the mixture of noble gases must be kept in a closed volume.
LOW STERILISATION RATE. The tests performed during EGGSTERILISATION project showed that in the industrial prototype (30 eggs in 30 seconds) the sterilisation rate was only 99%.