Eggs are part of many people's breakfast or dinner. Easy to find, simple to cook and a source of protein and other nutrients, they are popular with young and old alike. But eating a rotten or spoiled egg by mistake can cause a range of health problems, so it is important to check whether an egg is fresh as well as buying it.

Spoiled or contaminated eggs may contain harmful bacteria. Infection with Salmonella in particular can cause food poisoning. Symptoms after eating a rotten egg can include nausea, vomiting, diarrhoea, stomach pain and fever.

Some people may also feel discomfort such as gas, bloating or heaviness in the stomach. A bacterial infection can lead to inflammation of the gut and other more serious problems. Food-borne infections can be riskier for children, older people and those with weak immunity.

A common way to check freshness is the water test. Fill a large bowl with water and gently lower the egg in. A relatively fresh egg usually stays at the bottom, while an older egg is more likely to float.

This is because over time water and gas pass through the shell and the air cell inside the egg grows larger. The egg becomes less dense and may float.

If an egg has an unusual smell, a crack or any other suspicious change, it is safest not to eat it.

Some people hold the egg to their ear and shake it gently. If the sound of liquid moving inside is clearly audible, the egg may be old. Rather than relying on sound alone, it is better to check the smell, colour and normal appearance after breaking it.

Using light to see inside an egg is called candling. Holding an egg in front of a bright light can give some idea of the air cell or any unusual spots, but testing at home in this way cannot reliably detect every kind of contamination.

When buying packaged eggs, check the date on the pack, the storage instructions and whether any eggs are cracked. Eggs also need to be stored properly once you get them home.

If an egg has an unusual foul smell, odd colour or appearance when broken, throw it away rather than trying to cook it. Anyone who has severe vomiting, diarrhoea, fever or dehydration, or whose symptoms persist, after eating a rotten egg should see a doctor quickly.

The story drew on EatingWell and Everyday Health.

Source: Jagonews24. First published in Bengali on The Agro News.