How Are We Able to Taste Things?
We are able to taste things due to our taste buds and nose. The tongue is covered with little bumps. Inside these bumps are cells which form our taste buds. Nerves carry “taste messages” from these taste buds to the brain. We not only have taste buds on the tongue, but also on the roof of the mouth (palate). There are a few in other parts of the mouth, as well.
The average person has about 10,000 taste buds and they’re replaced every 2 weeks or so. But as a person ages, some of those taste cells don’t get replaced. An older person may only have 5,000 working taste buds. That’s why certain foods may taste stronger to you than they do to adults. Smoking also can reduce the number of taste buds a person has.
But before you give taste buds all the credit for your favorite flavors, it’s important to thank your nose. Olfactory receptors inside the uppermost part of the nose contain special cells that help you smell. They send messages to the brain.
Smell also adds to our sense of taste. Many foods wouldn’t taste as good as they do if we couldn’t smell them. That is why food loses some of its taste when we have a cold and our nose is stuffy.
Here’s how it works: While you’re chewing, the food releases chemicals that immediately travel up into your nose. These chemicals trigger the olfactory receptors inside the nose. They work together with your taste buds to create the flavor by telling the brain all about it!
So the next time you chomp on an apple or slurp up some soup, thank your tongue — and your nose! Without them, life wouldn’t have any flavor. Based on the information that is transported from the tongue to the brain, there are thought to be at least five basic qualities of taste. Many dishes are made up of a combination of different tastes. Some dishes taste sweet-sour, for example, while others are salty and savory. The basic tastes are:
Sweet: What we perceive as sweetness is usually caused by sugar and its derivatives such as fructose or lactose. But other types of substances can also activate the sensory cells that respond to sweetness. These include, for example, some protein building blocks like amino acids, and also alcohols in fruit juices or alcoholic drinks.
Sour: It is mostly acidic solutions like lemon juice or organic acids that taste sour. This sensation is caused by hydrogen ions, chemical symbol: H+, split off by an acid dissolved in a watery solution.
Salty: Food containing table salt is mainly what we taste as salty. The chemical basis of this taste is salt crystal, which consists of sodium and chloride. Mineral salts like the salts of potassium or magnesium can also cause a sensation of saltiness.
Bitter: Bitter taste is brought about by many fundamentally different substances. In total there are about 35 different proteins in the sensory cells that respond to bitter substances. From an evolutionary standpoint, this can be explained by the many different bitter species of plants, some of which were poisonous. Recognizing which ones were indeed poisonous was a matter of survival.
Savory: The “umami” taste, which is somewhat similar to the taste of a meat broth, is usually caused by glutamic acid or aspartic acid. These two amino acids are part of many different proteins found in food, and also in some plants. Ripe tomatoes, meat and cheese all contain a lot of glutamic acid. Asparagus, for example, contains aspartic acid. Chinese cuisine uses glutamate, the glutamic acid salt, as flavor enhancers. This is done to make the savory taste of foods more intense.