Extending the storage time of eggs at home or at retail would increase Salmonella food poisoning risks, says EFSA’s latest scientific opinion on public health risks from eggs. Experts focussed on the risk to consumers posed by Salmonella Enteritidis, the bacteria responsible for causing the highest number of egg-borne outbreaks in EU.
EFSA’s experts looked at the consequences of extending the sell-by date and best-before date for eggs eaten on their own or as ingredients in foods. The sell-by date is the last date shops are supposed to display eggs for sale; the best-before date is the period in which the eggs maintain their best quality, for example their texture and flavour.
If the sell-by date for household consumption is extended from 21 to 28 days for eggs, the risk of infections increases by 40% for uncooked and 50% for slightly cooked eggs respectively. In the worst case scenario, where the sell-by date is 42 days and the best-before date is 70 days, the risk is around three times higher than currently for both uncooked and slightly cooked eggs.
The results are similar for eggs used in catering establishments, which are usually collected directly from wholesalers, by-passing retail.
To calculate such estimates, EFSA experts used a quantitative model that allowed comparing the current situation regarding the storage of eggs in the EU with different possible scenarios, using different sell-by dates and best-before dates.
“If Salmonella is present inside eggs, it can multiply more rapidly as the temperature and storage time rise. However, thoroughly cooking eggs reduces the risk of infection”, explains John Griffin, Chair of the Biological Hazards Panel.
Keeping eggs refrigerated is the only way to reduce the increased risk of infections due to extended storage. However, if the sell-by date and best-before date were extended for more than three weeks, the risk increases- even with refrigeration in shops.
This scientific advice was requested by the European Commission to help inform any future developments on date marking for eggs. Consumer confusion about the meaning of date labelling contributes to food waste in the home.
Salmonella control programmes at EU level have led to a decline of Salmonella cases in humans over recent years. Salmonella in poultry has also decreased significantly, especially in laying hen flocks. The reduction of Salmonella levels in laying hen flocks is likely to be the main reason for the decline in human cases, since eggs are the most important source of human infections in the EU.
- While the best-before date appears on the package, the sell-by date is an instruction to shop staff and does not appear on the packaging.
- The model used was provided by the Australian Egg Corporation Limited and was modified by experts from the Food Standards Australia New Zealand and EFSA experts to include data relevant to the EU situation (such as storage practices and data on prevalence of Salmonella Enteritidis contaminated eggs).