WHITES THAT AREN'T WHITE yellow means the egg is old; green can mean an excess of riboflavin in the diet, or that a bird has eaten a weed called shepherd's purse; dark green indicates a bird has eaten oak or acorns (especially in ducks);
Off-color egg white, green or iridescent – Spoilage due to Pseudomonas bacteria, a very common type of bacteria that healthy people often carry without knowing it. This bacteria produces a greenish, fluorescent, water-soluble pigment in the egg white. If you come across an egg with an off-color egg white, discard it.
Older eggs (which are still safe to eat) tend to be more alkaline, which encourages a green reaction similar to that green ring you can get around a hard-cooked egg yolk. The green is harmless, but pretty much inevitable in older eggs.
The best way to determine if your egg is spoiled is by cracking it open into a bowl. If the egg white is pink or iridescent this is an indication of spoilage due to Pseudomonas bacteria. Some of these bacteria can make us sick when eaten and they will produce a greenish, fluorescent, water-soluble color.
A fresh egg should have a bright yellow or orange yolk and a thickish white that doesn't spread too far. If it's off, the yolk will be flatter and discoloured and the egg white will be far runnier. As we've already described, rotten eggs will also have a sulfuric smell to them.
You can't tell if an egg has salmonella just by looking at it. The bacteria can be present inside an egg as well as on the shell. Cooking food thoroughly can kill salmonella. Be aware that runny, poached, or soft eggs aren't fully cooked — even if they are delicious.
The frequency of Salmonella-contaminated eggs in Australia is very low. Despite this, there is a potential risk of illness from consumption of raw or lightly-cooked eggs, or the consumption of uncooked foods containing raw egg.
Look for any pink or iridescent discoloration in the yolk or whites, as this may indicate bacterial growth (2). If you notice any signs of discoloration, throw the egg out and wash the bowl with hot, soapy water before testing a new egg. You can also check to see if the whites or yolk of the egg are runny.
Does cooking eggs kill Salmonella bacteria? Yes, if you cook the eggs until both the white and yolk are solid. If you are cooking a dish containing eggs, make sure you cook it until the food is hot all the way through. It is best to avoid any uncooked foods or dishes that contain raw egg.
The eggs stored in cold temperature tend to undergo condensation when they are taken out to room temperature. This promotes the growth of bacteria over the egg shell, thereby contaminating the egg and making it harmful for human consumption.
The Centers for Disease Control estimates that 1 in every 20,000 eggs are contaminated with Salmonella. Persons infected with Salmonella may experience diarrhea, fever, abdominal cramps, headache, nausea and vomiting.
Eggs are one of nature's most nutritious and economical foods. But eggs can make you sick if you do not handle and cook them properly. That's because eggs can be contaminated with Salmonella, which are bacteria that make people sick.
To identify a rotten or old egg before cracking it open, the easiest thing to do is the float test. Place the egg in a glass of water. Fresh eggs will sink to the bottom, while bad eggs will float. (And should be thrown out.)
The most accurate way of testing whether your eggs have gone bad is to crack them open. If the yolk or white has any discoloration, the egg is no good. Discoloration is an indication of bacterial growth. If your eggs look good but have an off or sulfuric smell to them, they are bad.
Eggs that are expired but not spoiled may still be perfectly fine to eat. However, eating old eggs that have been damaged or contaminated puts you at risk of getting sick from contracting the foodborne bacterium Salmonella.
Although egg washing is not a requirement in Australia, sale of dirty eggs is prohibited by Food Standards Australia New Zealand (FSANZ). Any washing and sanitising process needs to reduce bacterial load on the eggshell, as visibly clean eggs can still be highly contaminated with Salmonella.
It's safe to consume raw eggs as long as some basic precautions are followed and the risks are understood. With any egg, there is always a low level risk of Salmonella bacteria being present on the eggshell exterior.
Raw eggs, and the dishes made with them, are responsible for many food poisoning incidents in Australia. It looks like this number is only going to increase with new strains of Salmonella bacteria entering the Australian egg supply.
To identify a rotten or old egg before cracking it open, the easiest thing to do is the float test. Place the egg in a glass of water. Fresh eggs will sink to the bottom, while bad eggs will float. (And should be thrown out.)
Carefully lower your eggs into fresh cold water using a spoon (you can do this in the pan if you're about to boil them). If the eggs stay at the bottom they're fresh; if the eggs float, however, they're stale and best avoided.
If refrigerated, eggs typically stay safe well after their expiration date. Regardless of what that date actually is, the optimal storage time for raw eggs in their shells, according to the USDA, is three to five weeks.
Still, as long as they remain free of contamination from bacteria or mold, they may still be safe to eat for days or weeks longer. Eggs have an average shelf life of 3–5 weeks. With proper storage, most eggs are still safe to eat after 5 weeks, though their quality and freshness will likely begin to decline.
If a person has any doubt about whether an egg has gone bad, they should throw it out. The main risk of eating bad eggs is Salmonella infection, which can cause diarrhea, vomiting, and fever.
While egg farmers supply a safe, clean, fresh product, it is possible for eggs to become contaminated by the food poisoning bacteria Salmonella. The good news is Salmonella is killed instantly at 74oC. So even if you are unlucky enough to get an egg with bacteria on it, the food will become safe by cooking it properly.