What is Taste?
Taste is the most important factor in a person’s decision about food. It is one of the five senses and it refers to the capability to detect the taste of substances such as food, minerals, and toxins. There are five true taste receptors (or buds) located not just on the tongue, but on the mouth palates (upper/soft) and in the throat as well. The upper, or hard palate is the roof of your mouth, and the soft palate, or muscular palate is the soft tissue in the back of your mouth that does not contain bone. Both palates contain taste buds.
Fun Fact: Why are they named taste buds? A taste bud is a microscopic rosette shaped cluster of 80-100 receptor cells in which chemicals are detected and is similar to the shape of a flower.
How do we taste?
Taste is actually a combination of volatile (compounds capable of emitting a gas) and non-volatile compounds that are either/both dissolved in saliva and/or act as odorants and pass to the brain via cranial nerves (glossopharyngeal and chorda tympani) or by way of the olfactory bulb through a back door (retro-nasal olfaction) where information about odor (aroma) is processed. (Olfactory Bulb – quarter sized structure that evaluates and processes odors in the nasal cavity)
Volatile vs. Non-Volatile Compounds:
Non-volatile compounds are sensed through taste buds. In the middle of each taste bud is a pore where saliva collects. When non-volatile compounds/chemicals enter the mouth, they are dissolved in the saliva pools in the middle of the taste buds and information specific to each compound are sent to the brain to be translated. Volatile compounds refer to how the compound itself smells. Volatile compounds can be emitted off of food by heat, but can also be released by chewing. Volatile compounds that are released in the mouth travel to the brain via the nasopharynx. Keep in mind that the brain processes odors differently based on if they come exteriorly from the nose or from inside the mouth.
More on taste buds: When you are born, you have on average 9,000 – 10,000 taste buds. But as you age, the number of taste buds present in a person’s mouth decreases – generally making people gravitate to food that is more spicy, sweet, or salty. There are four kinds of taste buds (or papillae).
1. Filiform Papillae – Small structure on the tongue that provide most of the bumpy appearance. Have NO taste function.
2. Fungiform Papillae – Mushroom shaped structures that are most densely on the edges and the tip of the tongue.
3. Foliate Papillae - Folds of tissue near the rear of the tongue where the tongue attaches to the mouth.
4. Cimcumvallate Papillae – Circular structures that form an inverted V near that back of the tongue.
The Tongue Map: Debunked
The ability to taste different flavors is not segmented on the tongue, but rather spread out and distributed all over the tongue. However as it is true that certain areas of the tongue can have different thresholds for taste perception, the differences are minimal. All areas of the mouth containing taste buds are sensitive to all taste qualities. There is one exception to this: the back of the tongue is very sensitive to bitter and this is to act as the “goalie” protecting us from ingesting spoiled, rotten, or poisonous foods.
The Five True Tastes
1. Bitter – evolutionarily speaking, the ability to taste bitter comes as a warning sign of plants/insects/animals producing toxins that are generally unsafe to eat. Not all bitter is bad. Coffee, Tea, Chocolate, and Grapefruit are all fruits/plants that contain bitter compounds but are safe for consumption.
2. Sour – comes mostly from citrus juices and vinegars. By-product of fermentation.
3. Salty – salty foods contain salt. Salt comes in many forms
4. Sweet – usually caused by sugar or sugar derivate. Can also be from alcohols (fruit) or amino acids (protein).
5. Umami (Savory, Delicious) – discovered in 1908 in Tokyo. Umami is actually a glutamate (a protein based amino acid) that has a “beefy/meaty/Savory” flavor, but lacking salt. Some vegetables like asparagus, tomatoes, and mushrooms also contain amino acids.
What about hot and spicy… are they tastes? NO! Hot and Spicy are pain signals sent by the nerves that cause pain and heat sensations.
What is flavor?
Flavor is the combined sense of taste, aroma/odor, and mouthfeel. FLAVOR IS NOT IN THE FOOD, IT IS IN THE BRAIN!!! As taste relies on the taste buds connection to the brain, triggering the five true tastes, and aroma is the brain’s ability to determine odorants (which makeup about 75% of the flavor impression), mouthfeel (or texture) provides the final link to determining flavor. But it is a larger concept that is based in quality, and how the brain accounts for quality in the taste equation that makes up the total taste experience. If something is different from the way we perceive it to be, that immediately plays a direct role on flavor perception. For example – does grainy gravy have the same flavor to you as nice, emulsified, incorporated gravy? Do potato chips taste as good if they are stale? Do French Fries from McDonald’s taste the same if they are limp and soggy? Does a nicely caramelized potato taste better than a boiled one? Temperature can also come into play when determining mouthfeel.
In summation, tastes come from the receptors in the brain that determine true tastes flavor is a sensation that is more than the sum of its parts. It is a complex process that has endless possibilities that is easily tweakable by the user to create a forever fully-customizable experience.