Gustation is a technical term for the sense of taste that most people have, which allows them to experience different flavors and tastes of foods and other objects a person may place in his or her mouth. This process involves nerves located in clusters of taste cells found in taste buds present in pores on the surface of the tongue and other parts of a person’s mouth. Gustation is typically one of the least acute senses a person has, though it is quite important for chefs and other culinary professionals.
The process of gustation begins when an object enters a person’s mouth and comes into contact with the tongue or other areas of the mouth. Though the tongue is typically associated with taste buds, they are present along the roof of the mouth and other places as well, though the sensitivity of these other surfaces often decreases with age. When food or other objects come into contact with these surfaces, water soluble tastes are able to enter pores that contain taste buds and a signal is then sent to the brain, which is interpreted as taste. There are five accepted tastes that a person can experience through gustation, which are sweet, saline, sour, bitter, and savory.
Classic understanding of gustation had initially only established four tastes that a person could experience, which were sweet, saline, sour, and bitter. Each of these tastes serves a specific biological purpose, beyond simple enjoyment of food. Bitter, for example, often serves as a warning that a natural food source is poisonous or might otherwise make a person sick, while sweet served to indicate that a food source was traditionally high in calories. These tastes were likely developed to help early humans identify safe food sources that provided sufficient nutritional value when the food entered a person’s mouth, before passing further into a person’s system.
A fifth taste that can be determined by taste buds during gustation was more recently identified, which is often called savory or umami. This taste is often associated with foods that are “meaty” such as beef and mushrooms. These foods are typically high in protein and this association likely led to the development of this taste as a positive flavor for many people.
Spiciness is not a flavor that is tasted through gustation, but is instead a chemical reaction that occurs when capsaicin interacts with the tongue and mouth. This reaction can occur through any taste buds, making spiciness a very strong sensation, and taste cells in taste buds are often damaged or destroyed by this reaction. These taste cells are replaced about every seven days, however, so such damage is typically only temporary. Smoking, exposure to radiation, and brain injuries can potentially decrease gustation sensitivity.