Is brown meat bad? Let explore. There has been that time when meat, especially beef, turned brown and you wondered whether it is still safe for consumption. Aside the cost involved in making the purchase, safety and taste also come into play. Indeed, a lot of customers judge whether meat is safe and fresh or not, based on its color. So, as a consumer, do you only decide to purchase when the meat is bright red?
how does meat get discolored?
Let’s do a little bit of science here. The compound in meat that gives it color is called myoglobin. This myoglobin contains iron, and stores oxygen in the cells, including muscles of animals. Depending on the amount of oxygen it has been exposed to and the chemical state of the iron, myoglobin typically takes on three forms, corresponding to three color manifestations.
If no oxygen is present, the form of myoglobin is called deoxymyoglobin. In this form, water is bound to the iron atom and the meat has a purple-red color. Next time you see beef being cut, observe the color. That’s deoxymyoglobin.
When the meat is exposed for about 15 to 30 minutes, the myoglobin undergoes oxygenation to become oxymyoglobin. This process is called blooming. Oxygenation is when molecular oxygen (from the normal air we breathe) binds to the iron atom. This makes the meat to look bright cherry red. The one most of us like to see before we are convinced that truly, this meat is fresh.
Now, when the myoglobin undergoes oxidation, then it is converted into metmyoglobin. This happens after several periods of exposure of the meat to oxygen. The brown color in meat we all avoid! We usually see this when meat is kept in storage for sometime or when the meat is left in the open for quite a long time.
IS THE MYOGLOBIN CONTENT OF ALL MEATS THE SAME?
No, all meats do not have the same amount of myoglobin. In fact, some animals have more, while others have less. That is why we have white meat and red meat. Animals with low myoglobin content generally give white meat. Examples are chicken, and other poultry. Then those animals having high myoglobin content give red meat. Beef is a common example.
The age of the animal also determines the myoglobin content. Older animals have higher myoglobin content, hence darker meat colors. In addition, the activity of the muscle is key. Muscles used for movement have more myoglobin content than those used for support. Can you think about why?… You remember that myoglobin stores oxygen in cells, right?
IS IT SAFE TO EAT DISCOLORED MEAT?
Meat may turn brown but it does not necessarily indicate spoilage. Though, spoiled meat can also turn brown. The indicators to use to identify whether browned meat is safe or not is that spoiled meat has a pungent smell which can be mild or strong depending on the level of spoilage. When touched, it has a tacky or sticky feel. So, it can still be safe to eat discoloured or browned meat when it does not smell unusual or has a sticky feel to touch.
WHAT NEW KNOWLEDGE HAVE YOU GAINED?
The next time you wash a piece of beef and you see a red liquid, it’s not blood. It’s actually myoglobin. All the blood has been drained during dressing. And more importantly, meat turning brown does not necessarily indicate spoilage. It’s just a manifestation of metmyoglobin.