When you go to the supermarket to pick up some red meat, you probably almost always see a red fluid packed inside of the plastic. This fluid is often mistaken for "blood," but that's actually not what it is at all.
Instead, this is actually a mixture of water and myoglobin. The latter is a protein from the muscle in the meat that gets broken down during transportation from the slaughter house to the supermarket.
This protein leaks out from the muscles as the meat is frozen and un-frozen due to the ice crystals expanding and rupturing muscle cells in the meat. There, it mixes with the thawed water. The red appearance comes from the presence of iron in the fluid.
Being that myoglobin is a natural protein that already exists in the muscle of the meat you're going to be eating, it's perfectly safe to eat. This isn't a chemical that gets added after the animal is slaughtered, and it certainly isn't blood, despite the common misconception.
