Red = Good. Brown = Bad. Right?
You associate bright cherry red color with the freshness of ground beef, right? That’s what we all look for when shopping at the supermarket. Faced with a choice between a package of bright red meat and a package of brownish meat, you go for the red meat every time.
But when you get home and crack open the package only to find brown meat under that bright red layer of exterior meat, what’s up with that? Has the supermarket wrapped fresh meat around old meat? Has the meat spoiled?
Short Answer: Do not fear. The meat is fine.
Long Answer: Continue reading to find out what’s going on.
It’s All About The Myoglobin
The color of fresh beef is the result of the interaction between a protein in beef muscles called myoglobin and oxygen. When beef is freshly butchered, myoglobin gives it a dark purple color. When exposed to air for about 15 minutes, myoglobin and oxygen interact to form oxymyoglobin. This changes the color of the meat to a bright cherry red. This process is known as “blooming” in the meat industry.
When beef is freshly ground and packaged, the exterior surface will be bright red, having been fully exposure to oxygen, while the inside meat will be purplish due to less exposure to oxygen. Some ground beef packaging, known as modified atmosphere packaging, introduces a precise percentage of oxygen around the meat which helps maintain a bright red surface appearance.
However, it’s a different story when it comes to the inside meat. As it sits with little exposure to oxygen, purplish myoglobin slowly converts to metmyoglobin.
Would you care to hazard a guess about the color of metmyoglobin? It’s brown!
Bottom Line It For Me
If you crack open a package of bright red ground beef and find it’s purplish or brownish on the inside, it’s safe to eat.
As for that package of brown looking ground beef at the supermarket…or lurking in the back of your refrigerator…it’s spoiled or will be soon. Do not use.
Want to learn more about the science behind the color of meat? Here are two good resources.