The process of slaughtering animals, cutting meat, usually leads to blood drainage. This means that industrial meats do not show traces of blood. Unless you purchased the meat as soon as the animal was slaughtered, the red you will see in the meat will not be from this bodily fluid.
What is that red liquid in the meat trays that we buy in the market?

Chunks of meat in trays – spm
If you bought meat in a package, you may notice the presence of a reddish liquid.
It should be remembered that 75% of meat is made up of water. When frozen, ice crystals break down muscle cells and release myoglobin, which mixes with water when food thaws and produces this particular liquid.
That red fluid that you think is blood is actually called myoglobin. Industrial meats are not sold with blood. They are only sold with myoglobin which gives this fluid its reddish color.
This is a substance of great importance because it is responsible for maintaining oxygen in muscle cells. As meat goes through consecutive freezing and thawing processes, the myoglobin mixes with the water present in the tissues and eventually drains off.
The latter is an iron and oxygen transport protein present in the heart and muscles connected to the skeleton of most mammals. Among them are cows, pigs and sheep, which are widely eaten around the world.
Chicken, pork, or fish generally do not have as high myoglobin levels as beef. That’s why they don’t release that particular red liquid.
Have you ever noticed that when cooking meat this liquid darkens and the meat shrinks?

Buy meat in the supermarket – spm
Myoglobin is rich in iron and when cooked it loses its reddish color and turns brownish. At the end of cooking, the meat decreases in size because its composition contains water and this evaporates during cooking.
You may be wondering if consuming myoglobin could pose a health risk. The answer is simple: it is a natural part of meat and it is not discouraged to consume it.
Myoglobin is part of the composition of tissues, so it will always be present because it has an important function in the animal’s body.