Why is hot food important?
Hot food is important because it changes the food we eat. It has a historical and current significance.
The heat created during cooking is an agent in a chemical process called denaturation that changes the proteins in food, breaking down the molecules and altering their physical and chemical properties. Depending on the cooked proteins, this causes the solubility to decrease or the hydrophobic proteins to bind to reduce the total area exposed to water. Denaturation affects the feel, taste, look and smell of food. A fried egg clearly shows denaturation and is a good example: the white, liquid egg white (albumen) reaches a fixed consistency and turns opaque white when heated. As with many denatured proteins, the process cannot be reversed, that is, you cannot return to the raw egg once it has cooled.
The denaturing process can be desirable because foods can look, taste, and smell better when cooked, and chemical changes can allow for the creation of new foods like meringue. To create a meringue, the chemical bonds between the egg molecules must be broken so that they can recombine with those of the sugar.
Cooking has another function because it also kills bacteria, parasites and viruses, making the food we eat safer. Bacteria like Salmonella and E. Coli can cause serious illness in humans and, at the very least, cause a nasty stomach upset. In the worst case, it can cause death. Children, the elderly, pregnant women, and the immunosuppressed are at increased health risk from serious illnesses caused by foodborne illness, and cooking well helps make food safer for them.
The heating process also softens food and makes it easier to digest. Cooked foods contain the same amount of calories as raw foods, but require less energy to digest. Cooking makes starches more digestible. Starches are not soluble in water, so they must be heated to break them down (a process called gelatinization). When they break down, they are easier for the stomach’s digestive juices to reach. Starchy raw foods are also generally unappetizing and tough (think raw potato) and cooking them makes them tasty.
Hot food also helps us warm up and is comforting. It is much more pleasant to come home in the winter with a hot stew than to come home with a lot of raw vegetables.
We prefer to have hot food as part of our diet. That’s not to say that raw foods don’t play a big role too, it’s just that humans like a mix of both and it benefits us to do this.
The ability to heat food was one of the things that helped humanity evolve into the dominant species that it is today. Cooking allowed us to digest some types of food more easily and we were able to kill bacteria and parasites, giving us safer food. Without the discovery of fire and the ability to cook food, we would not be in the position we are in now, and this means that the addition of hot foods to the human diet was a very important step forward in our evolution.