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You know how when you go to the grocery store, you’ll sometimes see beef that looks bright cherry red, and other times it might look more purplish-red or even brownish-red? Well, there’s a perfectly natural reason for those color variations.
It all comes down to the exposure to oxygen. Beef contains myoglobin, which is a protein that stores oxygen in the muscle. When myoglobin is exposed to oxygen, it turns that bright cherry red color that we typically associate with fresh beef.
However, if the beef hasn’t been exposed to oxygen for a while, the myoglobin loses its oxygenated form, and the meat takes on a more purplish-red hue. This is perfectly normal and safe to eat.
And if you see some beef that looks brown, that’s usually a sign that it’s been exposed to the air for too long, and the myoglobin has oxidized further. While it might not look as appetizing, it’s still safe to consume as long as it hasn’t spoiled.
So, in short, the color of fresh beef is mainly determined by how much oxygen the myoglobin in the meat has been exposed to. Isn’t it fascinating how something as simple as oxygen levels can create such a vibrant color palette in our food?
What Color Should Fresh Beef Be?
Beef is another name for cow meat. The optimum surface color of fresh beef is usually cherry-red, but other color variations are seen, colors like purple-red and brownish-red. Note that colour variations are not an indication of spoilage.
Most times the color of fresh beef can be a total turnoff to you when making a choice in the market. People tend to go for beef with a red colour more often. There is a scientific explanation about the varieties of fresh beef colour you find in the market. Knowing this priceless information will help you choose beef when next you visit the market.
Color Variation As A Result of Myoglobin
- Purple-red color: This color is possessed by beef that has not been exposed to air. The purple-red colour is a result of the myoglobin in the meat muscles and when myoglobin is exposed to air, it changes to oxymyoglobin, which gives the meat a pleasing cherry-red colour.
- Cherry-red color: The cherry-red colour is the optimum colour of fresh beef sold in the market. This color is highly unstable and short-lived. The colour changes quickly due to many factors like oxygen and myoglobin. To help retain the cherry-red colour of fresh beef, you can use a plastic wrap that allows oxygen to pass through.
- Brownish-red color: This color results when the meat has been exposed to either store lighting or sunlight for a long period. It can also result when the meat has been exposed to oxygen for a long period. When this happens, the oxymyoglobin reacts with the oxygen and forms metmyoglobin which is the pigment that gives fresh meat the brownish-red colour.
- Rainbow Color: Fresh beef can possess many colours, ranging from shiny green to silver color, but this does not mean that the meat is spoilt. Fresh meat is made up of different compounds like iron and fat. When light hits the compounds, it can cause the colours to split and cause a rainbow effect.
Color Variation As A Result of Animal Stress
When the cow is being transferred to the abattoir for slaughter, there are various factors which can impose stress on the cow. Such factors include environmental stress, nutritional stress, pre-slaughter stress and other stress factors.
These stress factors have a direct effect on the color and texture of the meat. Stress factors mainly cause fresh beef to have 2 distinct colours which are;
Pale red Color: This color of meat occurs when the cow is subjected to severe anxiety and fright caused by man-handling. Also when they engage in fights in their pens a few hours before they are slaughtered. All this results in biochemical processes in the muscles.
The biochemical processes cause the glycogen in the muscles to break down rapidly and this produces meat which is pale red. It is important to note that such meat has poor flavour. This meat color turns people off because it is not appealing to the eye and eventually, the meat becomes a waste.
Dark red color: A meat that is very dark in colour is indicative that the glycogen in the cow muscles was used up before slaughter. The glycogen gets used up during handling, transport and pre-slaughter.
Especially when the cows were not fed properly a day before the slaughter. Such dark coloured meats have inferior quality and less pronounced taste. Also, such meats have a shorter shelf life and can spoil faster than normal.
Is It OK to Eat Discolored Beef?
No, it’s generally not recommended to eat discolored beef. Discoloration can be a sign that the meat has spoiled or been contaminated with bacteria. While a slight browning on the surface is normal due to oxidation, any sliminess, off-odors, or green/grey/yellow tinting could indicate the presence of harmful microorganisms.
What Color Is Freshly Slaughtered Beef?
Freshly slaughtered beef has a bright, cherry-red color. This vibrant hue comes from the oxygenation of the myoglobin protein in the muscle tissue. Myoglobin is what gives beef its characteristic red color when exposed to oxygen.
As beef ages or is exposed to air over time, the bright red slowly turns to a duller brownish-red as the myoglobin becomes more oxidized. But that initial, freshly cut beef should have a very vivid, cherry-red appearance.
Why Is My Raw Beef Green in The Fridge?
If your raw beef has turned green or greenish-brown in the fridge, it’s a sign that the meat has spoiled and should not be eaten. The green coloration is likely due to the growth of spoilage bacteria like Pseudomonas, Lactobacillus, or Achromobacter.
These bacteria produce pigments that can cause meat to turn shades of green, blue, grey, or brown. While some slight discoloration on the surface is normal, an overall green color indicates advanced spoilage and increased risk of foodborne illness.
How Long Is Beef Good in The Fridge?
Raw beef can typically last 3-5 days in the refrigerator before starting to spoil. Ground beef tends to have a slightly shorter shelf life of 1-3 days due to the increased surface area exposed to air.
Proper refrigeration at 40°F or below is key, as warmer temperatures allow bacteria to multiply faster. Tightly wrapping beef in plastic, ziplock bag or storing it in an airtight container also helps slow spoilage. if the beef smells off, feels sticky or slimy, or has changed color, it’s best to discard it.
Be aware of the causes of meat colour variations so you can make the right choice in the market. Remember, a colour change does not necessarily mean that the meat is spoilt.
