Ishti studied medicine. He likes to write articles about things that interest him!
"Spicy" is not a taste, but you didn't know that, did you?
Yes, you heard me right! Spiciness is not a taste!
You may think you know what you are talking about and perhaps you are right. The Chicken Tortilla Soup you had today may be spicy, but spiciness is not one of the five basic tastes. There are only five basic tastes and they are: saltiness, sourness, sweetness and bitterness and umami. All the other tastes are a combination of the above five basic tastes.
But here is the thing: spiciness is not produced as a result of the combination of the basic tastes. Interesting, right?
Before explaining how you perceive spiciness, let me tell you a little about how we perceive taste.
Taste is basically the sensation that you get when you put something in your mouth. But that something must react chemically with the taste receptors in your mouth for you to taste it. Don't worry if you don't know what taste receptors are, just read on and you will understand.
I am going to tell you a little about the anatomy of the structures that enable us to taste food because without understanding the anatomy you won't understand the physiology of taste!
Anatomy of Taste
Stand in front of a mirror and look at the surface of your tongue. You will see that it is covered with numerous tiny knobs. These knobs are called papillae. There are four kinds of papillae: fungiform, filiform, foliate, and circumvallate. Except for the filiform papilla all the other contain numerous tastebuds.
Taste buds are small onion-shaped structures made of about 50-100 modified epithelial cells. There are two types of cells: gustatory or taste cells and sustentacular, or supporting cells.
The gustatory cells are the main cells that are responsible for transferring the sensation of taste to the brain.
On top of these cell are numerous microvilli or gustatory/taste hairs. These taste hairs contain numerous receptors called taste receptors.
The body and lower portion of the gustatory cells are attached to numerous nerve fibres. These nerve fibres are branches of the facial, glossopharyngeal and vagus cranial nerves.
The sustentacular cells are basically the supporting cells which maintain the onion shaped structure of taste buds. They are mostly located in the outer region of tastebuds.
The outer tips (top part) of these two types of cells are arranged in such a way that a taste pore is formed on the upper portion of the tastebuds. The taste hairs present on the gustatory cells protrude into these taste pores and reach the mouth cavity.
That's all the anatomy you need to know for now to understand how we perceive taste. Now let's take a look at what actually happens when you put something tasty in your mouth.
Physiology of Taste
When you put food in your mouth, the chemicals responsible for the taste of that food are dissolved by the saliva and are carried to the taste pores.
Once these chemicals reach the taste pores they bind with the taste receptors present on the taste hairs. This causes stimulation of the gustatory cells which in turn causes stimulation of the nerve fibers attached to the gustatory cells. These nerve fibers carry the signal to the gustatory cortex of the brain which interprets the signal and makes you aware of the taste.
And that is the basically how you taste something.
Technically speaking we don't actually taste the spiciness in spicy food! Spiciness is in fact a form of pain sensation! Surprised? To understand why it is a pain sensation we need to know a bit of how we perceive pain.
So How Do We Perceive Pain?
Pain is basically a protective mechanism of the body. Pain makes you aware of something that is damaging your body. It makes you move away from something that is causing damage to your body.
Just like how we perceive taste via the taste receptors present on the taste hairs of gustatory cells, we perceive pain via pain receptors. These pain receptors are also called nociceptors.
Nociceptors are mostly present on the outer layers of the skin and mucous membranes of the eyes, nose, mouth, etc. But they can also be found on some deeper structures like the periosteum, arterial walls, etc.
Anatomically or structurally speaking, nociceptors are just free nerve endings.
When something damages your body, these nociceptors become activated and sends signals to your brain which intreprets the signals and makes you feel pain so that you try to move away from the source of damage.
Generally speaking, three kinds of stimuli can activate nociceptors- mechanical, thermal and chemical.
A Little About the Three Stimuli That Cause Pain
Have you ever suffered from back pain? That's an example of mechanical pain. Did you ever burn your hand while cooking? That's an example of thermal pain.
So that leaves us with chemical pain, and I guess you already know where I am going with this, don’t you? Yes, spicy foods contain chemicals which actually irritate and stimulate the nociceptors present in our mouth and the pungency you feel depends on the amount of pain it inflicts on the nociceptors. And that's not the whole story! Nociceptors, as I have said, are basically free nerve endings and in the mouth they are the free endings of the trigeminal nerve. Some of the free nerve endings of the Trigeminal nerve also monitor temperature (thermoreceptor) and spices also stimulate some of these thermoreceptors in your mouth. And that is why you also get a burning (hot) sensation while eating spicy food!
So spiciness is basically a combination of the pain and burning sensation that you get when you eat spicy food! The process of how all this happens is called Chemesthesis.
"Chemesthesis" is defined as the chemical sensibility of the skin and mucus membranes. Chemesthetic sensations arise when chemical compounds activate receptor mechanisms for other senses, usually those involved in pain, touch, and thermal perception. These sensations can be aroused from anywhere on the skin and mucous membranes of the nose, mouth, eyes, etc. That is why when you put chili pepper on your skin or nose (!) you feel a sensation of heat (burning sensation). But of course it is harder for the chemesthetic receptor on the skin to become activated by chili pepper because the surface of the skin is covered by a layer of dead skin cells whereas the mucous membranes lack this barrier of dead cells.
So, technically speaking, spiciness is not a taste because it is not produced by taste buds and the nerve that carries the "spicy" signals to the brain is the trigeminal nerve whereas taste sensations are carried via the facial, glossopharyngeal, and vagus nerves.
More Fun Facts
- Do you know why you cry when you cut onions? It's also a form of chemesthetic sensation!
- The coolness of the menthol in your mouthwash is also because of chemesthesis!
- Do you know that metallic is considered to be a basic taste as it can not be produced by combining the five basic tastes! Blood has a metallic taste.
- Do you know that scientists are now thinking fattiness could be another basic taste?
Turtle 44 on December 12, 2019:
Angel on March 04, 2019:
So spicy goes with touch instead of taste, got it
:) on September 27, 2018:
Nicely worded article!
Amanda on September 24, 2018:
Surbhi on October 18, 2017:
This is awesome
shuaib on September 25, 2017:
...I like your content about taste.....I got a taste too when reading this article.....share more your articles regarding nervous system also....
markirlanda on April 11, 2017:
SO are you saying that it is physically possible to burn your mucos membranes (ie mouth) with very spicy food such as eating raw chillis? could this burn the taste buds?
curious to know!
Good post by the way
Nice Article on March 14, 2017:
Well written with good presentation of information. Thanks. I would want to challenge your title in a sense, not challenging you but the scientific definition of taste ;p
Should we be lining up our ideas of taste to it our should science be exploring taste in the context of our perception in order to be useful?
Seems to me this is all proof that we should expand our scientific definition of taste to include a broader range of sensations.
Sumaiyah Shoaib on October 04, 2016:
Really nice post... I got too much from this post.. Thank you:)
Felicia on September 19, 2016:
How does one come to love the "hotter the better"? Is it a conditioning of sorts (like environmental factors) And then the rest of us out here - why can we not tolerate the extreme heat of spicy foods like those who can? Appreciate feedback.
CJsciencestudent on September 17, 2016:
nice post very informational for my science project
Article bullshit on November 28, 2015:
Sorry to say but this article tried so hard to deny the taste of spicy by relating it to pain sensation that comes with it. So what this article is saying is that things which gives pain sensation aren't counted as a sense of taste. Therefore according to the article, acidic food (which are sour) does eventually gives a tangy feeling (pain), also will not be categorized under the sense of taste either. "Spicy" is not a term to describe the sensation of touch, but rather the taste. I am pretty sure people with sensitive sense of taste can easily tell the difference between the taste and stingy feeling when consuming spicy food or ingredients, such as chilli.
shweta shukla on August 30, 2014:
I love spicy food... My mum is Kashmiri.... Don't really care whether it is a taste or a sensation......
boniface on March 20, 2014:
i have been advise by my doctor to eat spicy food. I therefore want to know more about it
Julian Rixon from Cork, Ireland on November 03, 2013:
That was great and I really enjoyed reading it. I've just been doing some research into cat taste and this fills in some of the gaps. I think it's fascinating to compare human taste with that of other mammals. I only knew of four taste stimuli and unami was totally new to me!
Oyon B on June 26, 2013:
Great hub! Loved it. :)
Nhat Minh on May 17, 2013:
Wow! Very nice work of yours, I really appreciate it! Thanks :D
Ann-Christin from UK on October 27, 2012:
Great hub! I know what you mean about spiciness being a form of pain,if I have my chilli too hot it really is pain :)
Ishti (author) on October 26, 2012:
Thank you for reading and the nice comments :)
Francesca27 from Hub Page on October 26, 2012:
Well done! I enjoyed your hub very much.
Debra Cornelius from Georgia on October 26, 2012:
Wow...never knew that! Thanks for sharing! Voted up!
Justsilvie on October 26, 2012:
Interesting and well done hub! Voted up and shared