Kids and vegetarian converts can all attest to going to the grocery store and seeing a package of beef sitting in a small pool of icky red juice. It doesn’t look appealing and can make some wonder about the morbidity of meat processing.
Well, wonder no more. What many of us have viewed as blood in the package is not actually blood at all. It’s myoglobin, a protein that gives raw meat that distinct bloody glow and forms the drippings you see under the plastic.
Myoglobin is contained in the muscles of an animal, and because of its deep coloration, it determines the darkness (red or white) of a meat. Its purpose is to store and transport oxygen in the muscles as they are used continuously. That oxygen is what’s used to metabolize energy.
Animals with large amounts of myoglobin are categorized as “red meat” while those with less myoglobin are considered “white meat”. White meats like poultry, pork, or seafood do not contain that much myoglobin because the muscle fibers (fast-twitch) are meant for fast bursts of energy – like fight or flight activity.
Red meat, on the other hand, is comprised of slow-twitch muscle fibers, which are made for longer, more enduring bouts of activity. When you see dark meat in certain animals (chicken legs, tuna), it’s because those areas of their muscles are used longer and more frequently. They have higher amounts of myoglobin in them.
The blood red color that you see is a combination of water and myoglobin, as blood is removed during the processing and packaging phase of meat production. Additionally, the dark color that appears during cooking is also because of myoglobin.
Heat changes the color of myoglobin from its red pigment to brown or a grayish color. The longer a red meat is heated, the more moisture is squeezed out and the more the color changes. Meat that is cooked for less time may still retain some of its original myoglobin “redness”.
When exposed to air, myoglobin naturally begins to darken, and is often an indicator of a meat’s freshness. Ever look in the meat case and notice some packs have a brown tinge? That’s because it’s been exposed to oxygen. If it happens in your own refrigerator, do an eye and sniff test to make sure it hasn’t gone bad.
One of the tricks that food scientists and commercial meat producers use is preserving myoglobin’s red pigmentation with carbon monoxide. That gives the impression that the meat is fresh because of its reddish or pink hue. And, depending on how well the meat was wrapped (e.g. vacuum-sealed), there’s a chance that oxygen hasn’t touched it.
There are some lovers of red meat who have a preference for consuming myoglobin as a drink. Although it sounds quite vampirey, proponents say it’s totally safe. Just know the next time you order your steak rare or get adventurous with steak tartare, it’s not blood that you’re eating, it’s myoglobin.
Have you been thinking the liquid is blood this whole time? Has your outlook on red and dark meat changed now? Are you on board with eating or drinking myoglobin straight?
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