Taste is one of your basic senses. It helps you evaluate food and drinks so you can determine what’s safe to eat. It also prepares your body to digest food.
Taste, like other senses, helped our ancestors survive.
The taste of food is caused by its chemical compounds. These compounds interact with sensory (receptor) cells in your taste buds. The cells send information to your brain, which helps you identify the taste.
Humans can recognize several types of tastes. Each taste has an evolutionary purpose, such as identifying spoiled foods or toxic substances.
We have receptors for five kinds of tastes:
Let’s look at each of these types of tastes more closely.
Generally, sweetness is caused by a form of sugar or alcohol. Certain amino acids may also taste sweet.
Scientists think we evolved to like sweetness because it helps us recognize energy-dense foods. Sweet foods are often high in carbohydrates, like glucose, which provide our bodies with fuel.
Examples of sweet foods include:
Sourness, or tartness, is the taste of acids. It’s brought on by hydrogen ions.
Often, spoiled or rotten foods taste sour. It’s thought we evolved to taste sourness to identify these types of harmful foods.
But not all sour foods are dangerous. For example, we can safely eat sour foods like:
Saltiness is usually caused by table salt, or sodium chloride, that’s added to food. It can also be caused by mineral salts.
Sodium is essential for electrolyte and fluid balance. So it’s believed we can taste saltiness to make sure we get enough sodium.
Salty foods include:
Bitterness is due to many different molecules. These molecules are usually found in plants.
However, many plants with bitter compounds are toxic. Our ancestors evolved to taste bitterness so they could recognize and avoid poison.
Not all bitterness is bad, though. We can typically tolerate bitterness at low amounts or when they’re combined with other tastes.
Bitter foods include:
Savory taste is caused by amino acids. It’s commonly brought on by aspartic acid or glutamic acid. Occasionally, savory is also called “umami” or “meaty.”
Some scientists think tasting savoriness helps increase our appetite and control protein digestion.
The following foods taste savory:
- meat broth
- aged cheese
- ripe tomatoes
Tastes being researched
Currently, scientists are researching other tastes such as:
- alkaline (opposite of sour)
Umami is the most recently discovered taste. It’s a Japanese term that loosely translates to “savory” or “meaty” in English.
In 1908, a Japanese researcher named Kikunae Ikeda found glutamic acid in kombu, a type of seaweed. He determined that the seaweed’s savory taste was due to the salts of glutamic acid. This includes monosodium glutamate, or MSG.
Since Ikeda’s initial discovery, umami substances have been identified in other foods. Umami was accepted as a new taste when scientists found umami receptors in our taste buds.
Taste and flavor aren’t the same thing.
- Taste refers to the perception of the sensory cells in your taste buds. When food compounds activate these sensory cells, your brain detects a taste, like sweetness.
- Flavor includes taste and odor. Odor comes from your sense of smell. Sensory cells in your nose interact with odor particles, then send messages to your brain.
You might associate odor with literally smelling something. But when you eat food, odor particles in your mouth also enter your nose through the nasopharynx. This is the upper area of your throat behind your nose.
Flavor is the result of this odor plus taste. There are many possible flavors, depending on the intensity of each odor and taste.
Your tongue contains thousands of tiny bumps called taste papillae. Each papilla has multiple taste buds with 10 to 50 receptor cells each. You also have taste receptor cells along the roof of your mouth and in the lining of your throat.
When you eat, the receptors analyze the chemical compounds in your food. Next, they send nerve signals to your brain, which creates the perception of taste. It also enables us to associate different tastes with different emotions.
Contrary to popular belief, the entire tongue can detect all five tastes. There isn’t a “zone” for each one. However, compared to the center of your tongue, the sides of your tongue are more sensitive to every type of taste.
The exception is the back of your tongue. This area is extra sensitive to bitterness, which is thought to help us sense toxic foods before we swallow them.
Some health conditions or injuries can impair your taste.
- upper respiratory infections
- middle ear infections
- radiation therapy of the head or neck
- taking certain medications, like antihistamines and antibiotics
- exposure to some chemicals, like insecticides
- ear, nose, or throat surgery
- wisdom tooth extraction
- head injury
- dental problems
- poor oral hygiene
- hypogeusia (loss of a certain taste)
- ageusia (loss of taste)
- dysgeusia (altered sense of taste)
Humans can detect sweet, sour, salty, bitter, and savory tastes. This allows us to determine if foods are safe or harmful to eat.
Each taste is caused by chemical substances that stimulate receptors on our taste buds.
Your sense of taste lets you enjoy different foods and cuisines. If you notice any changes in your sense of taste, make an appointment to see your doctor.