In that case, the meat is still safe to eat, provided it doesn't have any other indicators of spoilage (read more on that below). However, if the exterior of the meat, or a majority of the package contents, has turned gray or brown, then it's a sign that the meat is beginning to spoil and should be tossed immediately.
Since the meat has turned grayish, it is safe to eat, just as long as you cook it well. To help make your ground beef safe to eat, check its color before cooking. If it's still a bit light in color, cook it until it turns red and then check to see if there are any gray areas in it.
If you're wondering why your steak turned gray in the fridge, it's likely because of a process called oxidation. When meat is exposed to oxygen, it turns red or brown. But when it's exposed to oxygen and moisture, it turns gray. This can happen when meat is stored in the fridge for too long.
However, steak that's been in the refrigerator for several days may also turn grey, indicating that it may have been exposed to more oxygen in the refrigerator. Still, this doesn't necessarily mean that it's not safe to eat, especially if it doesn't have an off-putting smell or slimy texture.
Why does raw steak change color to gray? Gray color indicates that oxygen hasn't touched the surface. Once oxygen touches the meat, it turns red again. Gray or brown color throughout the meat indicates it's starting to spoil and isn't safe to eat.
Signs of spoiled meat
A bad smell, a slimy or sticky texture as well as discolouration are all potential signs of spoilage on meat, seafood or chicken. Even though meat may not necessarily be bad, you should err on the side of caution. Look at, touch and smell the meat for important clues about its freshness.
When meat is frozen, it undergoes a process called oxidation. This is when the fats in the meat start to break down and react with the oxygen in the air. This is what causes the meat to turn brown or gray. This is a natural process and does not mean that the meat is spoiled or unsafe to eat.
In some cases, bacteria can cause the meat to turn brown, but when this happens, the bacteria will also create a smell. So, the next time you find some discolored meat in the fridge, give it a sniff. It it smells fine, remember it's just a little oxidation and will be perfectly fine to eat.
The color pigment in cured meats is very unstable; when light oxidizes the red cured meat pigment nitric oxide myoglobin (nitrosomyoglobin), metmyoglobin nitrite is formed and the ham turns grey.
Raw steak could stay at its peak quality and freshness for 3 to 5 days in the fridge set to 40 degrees F or below. This temperature slows down spoilage and the growth of foodborne bacteria.
As oxygen decreases, uncooked ground beef will slowly change to dull red to tan and eventually brown. Those changes occur primarily because of a loss of oxygen. Packaging slows the loss of oxygen, but the change in color continues to occur even if the product is stored in a refrigerator or other cold area.
However, exposure to store lighting as well as the continued contact of myoglobin and oxymyoglobin with oxygen leads to the formation of metmyoglobin, a pigment that turns meat brownish-red. This color change alone does not mean the product is spoiled.
Over time, the presence of oxygen eventually turns the meat to a greyish-brown color. This is due to the continued oxidation of the myoglobin, which becomes metmyoglobin. The New South Wales Food Authority explains that a larger surface area means minced meat is more likely to turn gray than whole cuts.
This may be the first thing you notice if your beef has gone bad, even before you open the fridge. Spoiled beef will develop a scent to it similar to ammonia or sulfur. In short, it won't smell good. Occasionally ground beef will develop a light smell if it's been in airtight packaging, and that's alright.
But as any poultry starts to go bad, it will start to turn an unpleasant shade of gray. If that pink hue starts to look slightly dull then it's time to use up your ground turkey immediately, and if it has a gray tint (even just a slight one), then it's time to toss it.
If only the interior is gray, you can bet that oxygen hasn't touched it to turn it red. This means ground beef with a gray interior is safe to eat. On the other hand, meat that looks gray or brown all over (on the inside as well as the top layer) has likely begun to spoil and is not safe to eat.
The first step in determining whether your lunch meat has spoiled is to examine its color. Has it changed in any way? If the meat has taken on a pale gray, brown, or yellow hue, it's probably not safe to eat. It's also time to toss it if it's grown any mold.
Do not consume the meat if you notice any suspicious changes to its smell or appearance. For example, you should discard the meat if it is emanating an unpleasant smell, if a viscous, sticky film appears on it, or if there is mold growth, Seveau says.
Obvious signs of spoilage, like mold, are clear indicators that you'll be tossing that cut and buying a new one. Other tell-tale signs of spoilage include meat that looks slimy, shiny, crusty, and/or off color. Raw beef should ideally be a beautiful red or even purplish hue and look moist but not wet.
This darkening is due to oxidation, the chemical changes in myoglobin due to the oxygen content. This is a normal change during refrigerator storage. Brown or grey coloring on meat doesn't automatically signify that it has gone bad, but it can signify it has had more time to oxidize.
That colour actually indicates a lack of exposure to oxygen, which is normal. Grocery stores will often discount meat, such as ground beef, that has turned brown, though it's well within its shelf life. If the meat turns brown or grey on the outside, though, it's likely not yet unsafe, but it is beginning to rot.
That said, if the top layer of beef has turned gray or brown (and it was never frozen), it's time to throw the package out.
What happens to meat that's frozen too long? Food that is stored in a freezer at zero degrees will be safe to eat indefinitely.
For raw ground meats, poultry, seafood and variety meats (liver, tongue, chitterlings, etc.), refrigerate them only 1 to 2 days before either cooking or freezing. Beef, veal, lamb and pork roasts, steaks and chops may be kept 3 to 5 days.