Over time after slaughter, animal meat undergoes a process called aging, which involves post-mortem stiffening and acidification that gradually hardens the meat, but at the same time, natural enzymatic processes tenderize it and deepen its flavor. Meats from cows, pigs, chickens, fish, and more age at different rates, and understanding this and eating them at the right time will help you enjoy the best flavor.
For us, meat is an important part of the table. It tastes great whether it’s raw or grilled, and nutritionally, there’s no better source of protein than meat. It’s also rich in essential nutrients like iron, zinc, and B vitamins, which help maintain stamina and build muscle. The main nutritional components of meat play an important role in maintaining modern health and are hard to replace with other foods. Therefore, meat is not just a food, but a precious gift from life that is essential for sustaining our lives.
When we eat such meat, we don’t feel very guilty about killing an animal. When we see red meat with a little blood on it, most of us think of eating it, and few of us think of it as horrible. But the truth is, meat is an animal carcass. When a person dies, their body temperature drops, causing them to become cold and stiff, and over time after slaughter, meat goes through a post-mortem stiffening process that eventually leads to decomposition. We are eating a carcass that is in the middle of this process.
Here’s how an animal carcass, or meat, goes from postmortem stiffness to decomposition. When an animal is first slaughtered at a slaughterhouse, for a while, its flesh tries to stay in a similar state to when it was alive, barely surviving on a substance called ATP in its muscles. ATP is the substance used to make energy, or in other words, life force. But this substance, ATP, needs oxygen to be made normally. However, since the animal is already dead and unable to breathe, ATP is slowly used up, and as a last resort, the muscles begin the process of making ATP without oxygen. During this process, the muscles break down a storage substance called glycogen, and along with ATP, they also produce an acid called lactic acid, which gradually acidifies the muscles as it builds up.
When muscles become acidic, the enzymes that break down ATP are activated. The muscles begin to contract as their structure breaks down, and at the same time, they gradually lose their ability to hold water. Over time, the muscles stiffen, a state known as maximum postmortem stiffness. During this process, the meat hardens and loses moisture, gradually becoming drier. As the muscles contract and stiffen, they continue to acidify because the process of making ATP continues to use up the remaining ATP. However, after a certain amount of acidification, the enzymes that digest muscle protein are activated, this time to slowly break down the protein.
This change is understood as a process of aging, but it’s actually a sign of the beginning of spoilage. As the proteolytic enzymes work, the meat gradually becomes softer, and the water retention that keeps it juicy returns, making it more flavorful. When meat is properly aged, it becomes particularly flavorful and its tissues soften, which makes it more chewy. For this reason, many people prefer to age their meat before eating it, and have even studied different methods of aging to bring out the best flavors.
All living things, not just the cows, pigs, chickens, and fish that we usually eat, go through this maximum post-mortem stiffness when they die and decay past the ripening stage. However, different animals go through all of these stages at different rates after slaughter. Usually, animals that are large and have used a lot of muscle while alive are slower, so they take longer to mature. For example, the maximum post-mortem stiffness is one day for cattle, half a day for pigs, and two hours for chickens, and the meat is considered fresh and at its best after this time.
Fish is a different story. Fish has softer muscle tissue and looser connections, so its post-mortem stiffness is shorter. Sashimi, the practice of slicing fish and eating it right away, is to enjoy the chewy texture of the fish while it is still in the beginning stages of post-mortem stiffness. Therefore, it is common to sashimi fish when it is in its post-mortem stiffness, shortly after it is caught, to enjoy its texture.
In conclusion, by understanding the characteristics of each meat and taking advantage of the changes in its state, you can enjoy your favorite meat dishes at their best.
