Is smell a subset of taste or is it the other way round? Or how i fail at google

[Damian79]

I cant seem to find a straight answer when i google.  Sorry if this is a lame question.

[Barry Egan]

the rag dipped in chloroform should be applied to the mouth, if that's what you're asking.

[lennedsay]

You might be better off looking through your school's online library, if you're in college. When I was in high school/college, my professors started saying that researchers and scientists are only finding out that they know far far less about the tongue than they thought, in relation to smell and to taste buds. Basically everything they knew was true probably wasn't, so check the dates on anything you do find.

[Damian79]

Shit should have added "yahoo" to my search this is what i found:

Yeah, it's true.

Go try the famous "apple-potato experiment". Cut an apple and a potato into cubes, close your eyes, and have a friend give you a piece of one or the other while pinching your nose and with the back of your nose closed off (like when you're swimming). If you don't have a friend, put the chunks on a plate, close your eyes and pick random bits. You won't be able to tell them apart - until you let go of your nostrils for even a second. The scent enters your nose and you immediately realize which it is!

You can't know in advance which is which though. Your brain will assume the smell is there and interpret it for you even without scent. Biology is wierd like that.

But yeah, the vast majority of taste is actually smell, and very little of smell is taste. You lose your sense of taste and you can still enjoy most food, but you lose your sence of smell and everything tastes like potatoes. Well, not quite, but you get my drift, I hope.

Lennedsay, I'll do that thanks.  

[Pringo]

If you're asking this in terms of something like food, you might be thinking of flavour which I believe contains both elements of taste and smell.

Other than that I think taste and smell are more or less completely independent senses. I'm definitely not a biology expert though.

[Damian79]

Pringo:  Hmm.  Thanks.

As for the tongue identifying stuff:

Thank you for asking such an interesting question. Yes, the tongue does have distinct taste areas, but they are almost microscopic. That is why you might not have been able to detect specific tastes, according to the older notion of specific large areas being specific to the four tastes: sweet, sour, salt, and bitter.

There actually is a fifth taste, just recently described at the taste-receptor level...at the level of the taste pore. The taste is called "umami" and was described about 90 years ago by a Japanese physiologist (Kikunae Ikeda). He said the taste was due to one of the amino acids (portions of protein) called "glutamate." You can find a short news article about this in Science, volume 287, p. 799 (4 February 2000), or go on-line at www.sciencemag.org. The taste is found in protein-rich foods, such as soy sauce...we call it 'shoyu' here in Hawai'i..., yeast pastes, and meat broths.

Each taste is detected by a specialized organ called the taste pore. You have a lot of them on your tongue and around the lining of the mouth. They have different shapes (circumvallate, foliate, and fungiform), but apparently each taste pore can detect more than one taste, depending upon the nerve endings contained in the pore. There is a really good article in The American Scientist (the publication of Sigma Xi, an organization to which I belong), volume 82 (Nov/Dec 1994). It is written at a fairly advanced level, so you might want someone who knows something about physiology to help you go through it.

So, regarding your project, you might have to go more in-depth than just the 'old' idea of four distinct areas of the tongue mapping onto four tastes. Its a lot more complicated than that, especially with the fifth taste finally being confirmed at the molecular level. Good luck!

[Damian79]

Even more courtesy of wikipedia on the tongue:

Fattiness
Recent research has revealed a potential taste receptor called the CD36 receptor to be reacting to fat, more specifically, fatty acids.[34] This receptor was found in mice, but probably exists among other mammals as well. In experiments, mice with a genetic defect that blocked this receptor didn't show the same urge to consume fatty acids as normal mice, and failed to prepare gastric juices in their digestive tracts to digest fat. This discovery may lead to a better understanding of the biochemical reasons behind this behaviour, although more research is still necessary to confirm the relationship between CD36 and the perception of fat.

[edit] Calcium
In 2008, geneticists discovered a CaSR calcium receptor on the tongues of mice. The CaSR receptor is commonly found in the gastrointestinal tract, kidneys and brain. Along with the "sweet" T1R3 receptor, the CaSR receptor can detect calcium as a taste. Whether closely related genes in mice and humans means the phenomenon may exist in humans as well is unknown.[35][36]

[edit] Dryness
Some foods, such as unripe fruits, contain tannins or calcium oxalate that cause an astringent or rough sensation of the mucous membrane of the mouth or the teeth. Examples include tea, red wine, rhubarb and unripe persimmons and bananas.

Less exact terms for the astringent sensation are "dry", "rough", "harsh" (especially for wine), "tart" (normally referring to sourness), "rubbery", "hard" or "styptic".[37]

In the Indian tradition, one of the 6 tastes [38] is astringency (Kasaaya in Sanskrit, the other five being sweet, sour, salty, bitter and hot/pungent).

In wine terms, "dry" is the opposite of "sweet" and does not refer to astringency. Wines that contain tannins and that cause astringent sensations in the mouth are not necessarily classified as "dry", and "dry" wines are not necessarily astringent.

[edit] Metallicness
Most people know this taste (e.g. Cu2+, FeSO4, or blood in mouth), however it is not only taste, but also olfactory receptors at work in this case.[39] Metallic taste is commonly known, however biologists are reluctant to categorize it with the other taste sensations. One of the primary reasons is that it is not one commonly associated with consumption of food. Proponents of the theory argue that the sensation is readily detectable and distinguishable to test subjects.

[edit] Prickliness or hotness
Main articles: Piquance, Capsaicin, and Scoville scale
Substances such as ethanol and capsaicin cause a burning sensation by inducing a trigeminal nerve reaction together with normal taste reception. The sensation of heat is caused by the food activating nerves that express TRPV1 and TRPA1 receptors. Two main plant derived compounds providing this sensation are capsaicin from chili peppers and piperine from black pepper. The piquant ("hot" or "spicy") sensation provided by chili peppers, black pepper and also other spices like ginger and horseradish plays an important role in a diverse range of cuisines across the world, such as Ethiopian, Peruvian, Hungarian, Indian, Korean, Indonesian, Lao, Malaysian, Mexican, Southwest Chinese (including Sichuan cuisine), and Thai cuisines.

If tissue in the oral cavity has been damaged or sensitised, ethanol may be experienced as pain rather than simply heat. Those who have had radiotherapy for oral cancer thus find it painful to drink alcohol.[citation needed]

This particular sensation is not considered a taste in the technical sense, because it is carried to the brain by a different set of nerves. Although taste nerves are also activated when consuming foods like chili peppers, the sensation commonly interpreted as "hot" results from the stimulation of somatosensory (pain/temperature) fibers on the tongue. Many parts of the body with exposed membranes but without taste sensors (such as the nasal cavity, under the fingernails, or a wound) produce a similar sensation of heat when exposed to hotness agents. In Asian countries within the sphere of mainly Chinese, Indian and Japanese cultural influence, Piquance has traditionally been considered a sixth basic taste.

[edit] Coolness
Some substances activate cold trigeminal receptors. One can sense a cool sensation (also known as "fresh" or "minty") from, e.g., spearmint, menthol, ethanol or camphor, which is caused by the food activating the TRPM8 ion channel on nerve cells that also signal cold. Unlike the actual change in temperature described for sugar substitutes, coolness is only a perceived phenomenon.

[edit] Numbness
Both Chinese and Batak Toba cooking include the idea of 麻 má, or mati rasa the sensation of tingling numbness caused by spices such as Sichuan pepper. The cuisine of Sichuan province in China and of North Sumatra province in Indonesia, often combines this with chili pepper to produce a 麻辣 málŕ, "numbing-and-hot", or "mati rasa" flavor.[40]

[edit] Heartiness (Kokumi)
Some Japanese researchers refer to the kokumi in foods laden with alcohol- and thiol-groups in their amino acid extracts which has been described variously as continuity, mouthfulness, mouthfeel, and thickness.

[edit] Temperature
Temperature is an essential element of human taste experience. Food and drink that—within a given culture—is considered to be properly served hot is often considered distasteful if cold, and vice versa.

Some sugar substitutes have strong heats of solution, as is the case of sorbitol, erythritol, xylitol, mannitol, lactitol, and maltitol. When they are dry and are allowed to dissolve in saliva, heat effects can be recognized. The cooling effect upon eating may be desirable, as in a mint candy made with crystalline sorbitol, or undesirable if it's not typical for that product, like in a cookie. Crystalline phases tend to have a positive heat of solution and thus a cooling effect. The heats of solution of the amorphous phases of the same substances are negative and cause a warm impression in the mouth.[41]

[Tieno]

My grandmother lost her sense of smell a few years ago and she says food doesn't taste as well as it used to.

[chronovore]

Weird. I always heard of "umami," but that's the first I've ever seen of "kokumi." Same thing, right?

[Damian79]

I think they are different things.