Taste

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**Taste** is one of the five main senses that helps people and animals enjoy and understand the food they eat. It allows us to notice different flavors, such as sweet, salty, sour, bitter, and umami (a savory taste). Taste happens when special cells on the tongue, called taste buds, sense the chemicals in food and send messages to the brain. The study of taste is called gustation. Scientists study how it works in the body, how it changes with age, and how it affects health and eating habits.

Taste begins in the mouth, mostly on the tongue. On the tongue, there are small bumps called papillae. Inside these bumps are tiny structures called taste buds. Each taste bud has special cells that can detect chemicals in food. When you eat or drink, these chemicals mix with saliva and touch the taste buds. Each taste bud contains taste receptor cells that send signals to the brain when they sense a taste. These cells respond to five main types of taste: sweet, salty, sour, bitter, and umami. Each type of taste is detected by different receptors. For example, sweet receptors react to sugars, while bitter receptors react to bitter foods. The signals from the taste buds travel through nerves to the brain stem. It then travels to a part of the brain called the gustatory cortex, where the brain understands the flavor.

There are five basic tastes that our tongues can sense: sweet, salty, sour, bitter, and umami. Each of these tastes helps us understand what we are eating. It can tell us whether something is safe or good for our bodies. Sweet taste usually comes from sugars. It tells us that food has energy, like fruits, candy, or honey. Our bodies need some sugar for fuel, so we naturally like sweet things. Salty taste comes from salt, or sodium, which is important for our nerves and muscles. Foods like potato chips or pretzels taste salty. Salt also helps bring out other flavors in food. Sour taste is found in foods like lemons, vinegar, and yogurt. It comes from acids in the food. Sour tastes can be refreshing, but they can also be a warning that food might be spoiled. Bitter taste is often sharp or unpleasant. It is found in some vegetables, like kale or Brussels sprouts, and in coffee or cocoa. Bitter tastes can warn us about toxins, but many healthy foods are slightly bitter. Umami is the taste of protein-rich foods. It is a savory or meaty flavor found in foods like cheese, soy sauce, mushrooms, and meat. The word “umami” comes from Japanese and means “delicious taste.”

Taste is just one part of what we call flavor. When we eat something, we do not just taste it. We also smell it, feel its texture, and notice its temperature. All of these things combine to create the full experience of flavor. Smell plays a big role in flavor. When we chew food, tiny scent particles travel from the mouth to the nose. This is why food can seem tasteless when your nose is blocked. Texture also affects flavor. Crunchy, soft, creamy, or chewy foods all feel different in the mouth, and this changes how we enjoy them. For example, smooth chocolate and crunchy chips may both be salty or sweet, but they feel very different to eat. Temperature matters too. Hot soup tastes different from cold soup, even if it has the same ingredients. Some flavors are stronger or weaker depending on how warm or cold the food is.

The main function of taste is to help us decide what to eat and what to avoid. Taste lets us know if something is sweet, salty, sour, bitter, or umami. This helps us find food that is safe, healthy, and full of the nutrients our bodies need. Taste protects us from harm. Bitter or very sour tastes can warn us that food might be spoiled or poisonous. In the wild, many toxic plants taste bitter, so animals (and humans) have learned to be careful with those flavors. Taste also helps us enjoy food. When we taste something sweet or savory, it can make eating more pleasant. This enjoyment encourages us to eat enough food to stay healthy and get energy. Taste can guide our eating habits. People may learn to like or dislike certain tastes over time. Culture, family, and personal experiences all shape what flavors we enjoy. This helps explain why food preferences are different around the world.

Taste is important for more than just eating. It connects to our health, culture, and personal experiences. What we like to eat can affect how we feel, how we grow, and even how we connect with others. Taste is different for each person. Some people love spicy foods, while others do not. Some might enjoy bitter vegetables, while others find them hard to eat. These differences happen because of genetics. Our genes help decide how strongly we taste things and what flavors we prefer. Culture also shapes our taste. People in different parts of the world grow up with different foods. For example, one culture might eat a lot of spicy dishes, while another enjoys mild or sweet flavors. As we grow up, we get used to the tastes around us and learn to like certain foods. Experience plays a role too. If you try a food many times, you may learn to like it even if you did not like it at first. Memories and emotions also affect how we feel about certain tastes. A food that reminds you of a happy time might taste better to you.

## Basic tastes 
### Bitterness 
Many common foods are bitter, like coffee, bitter melon, olives and citrus peel.

Bitterness is of interest to those who study evolution, as well as various health researchers. Many naturally bitter compounds are toxic. The ability to detect bitter-tasting, toxic compounds at low thresholds may have a protective function, but some test have not confirmed this. Plant leaves often contain toxic compounds, and among leaf-eating primates there is a tendency to prefer immature leaves. Young leaves tend to be higher in protein and lower in fiber and poisons than mature leaves. Amongst humans, various food processing techniques are used worldwide to detoxify otherwise inedible foods and make them palatable.

Animals which eat a lot of bitter plant material, such as browsers do have ways of dealing with it.  They produce tannin-binding proteins, which other animals do not.  Tannins are bitter compounds common in material from trees and bushes, though not grass.

### Saltiness 
Saltiness is felt when there is sodium in the food.  A common spice that is salty is common salt, sodium chloride.

### Savouriness 
Savouriness (or savoriness) is the taste of  foods. It is also known by the Japanese word , and comes from umai, which means 'yummy'. This taste was known for a long time, but only became an official scientific term in 1985.

To taste savoriness, your tongue has special parts that detect amino acids that are in foods like meats and cheeses.

### Sourness 
Sourness is tasted when acids are on your tongue. Many foods have acid in them and are sour, like lemons and vinegar.

### Sweetness 
Sweetness is a taste felt when sugars are in the food. Most people consider sweetness to be a  taste. Many common foods that are sweet are, Candy, Chocolate, Cake, and some Fruit. Many of these are artificially sweet.

## Taste-related 
### Spicy/hot 
This sensation is not a special sense of taste because it does not have specific taste buds. It is a complex sensation.

Substances such as ethanol and capsaicin cause a burning sensation called chemesthesis, piquance, spiciness, hotness, or prickliness. Two main sources of  this sensation are capsaicin from chili peppers and piperine from black pepper.

Foods like chili peppers activate nerve fibers directly giving the sensation of "hot". Many parts of the body with exposed membranes but no taste sensors (such as the nasal cavity, under the fingernails, surface of the eye (cornea) or a wound) produce a similar sensation of heat or sometimes pain, when exposed to such chemicals.

### Other sensations 
The tongue can also feel other sensations not generally included in the basic tastes. These are largely detected by the somatosensory system.

Also, it is known that smell and sight contribute to the overall sensation of eating and drinking. The temperature of food makes a difference to its appreciation.

The strange coolness of spearmint, menthol and camphor is caused by their molecules triggering a sensory system which normally works to sense low temperatures.

There is still much to learn about the taste system. Consider, for example, the tastes of ginger and horseradish.

## References