Fat is a flavor?

Researchers at Australia's Deakin University have published a paper in the British Journal of Nutrition showing evidence that human beings can taste fat -- that is, they can distinguish between two flavourless solutions in which one has more fat than the other.

I believe that this is true -- and that fat can offset bitterness the same way that sweet can. For example, raw cacao nibs mixed with cashew nuts taste sweet and chocolatey.

"We know that the human tongue can detect five tastes -- sweet, salty, sour, bitter and umami (a savoury, protein-rich taste contained in foods such as soy sauce and chicken stock)," Russell Keast, from Deakin University, said Monday.
"Through our study we can conclude that humans have a sixth taste -- fat."
Researchers tested 30 people's ability to taste a range of fatty acids in otherwise plain solutions and found that all were able to determine the taste -- though some required higher concentrations than others.

Australian researchers say fat is 'sixth taste' (via Kottke)

(Image: Beale's Open Kettle Rendered Pure Lard, a Creative Commons Attribution photo from Steve Snodgrass' photostream)

Previously:

I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.

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Yet another taste to add to the list, yay. Not all nationalities list the same ones the English speaking world tents to. Wikipedia’s page lists the following recognised tastes:

Bitterness

Saltiness
aka sodium ions

Sourness
aka acidity

Sweetness

Umami
aka Savoriness, glutamate

Fattiness
aka CD36 receptor

Calcium
aka CaSR calcium receptor

Dryness
aka tannins, calcium oxalate, astringency, dry, rough, harsh, tart, rubbery, hard, styptic (tea, red wine, rhubarb, unripe persimmons and bananas)

Metallicness
aka Cu2+, FeSO4, blood.

Prickliness or hotness
aka Scoville scale, Piquance, TRPV1 and TRPA1 receptors (ethanol, chili peppers/capsaicin, black pepper/piperine, ginger, horseradish)

Coolness
aka TRPM8 ion channel, fresh, minty (spearmint, menthol, ethanol or camphor)

Numbness
aka tingling numbness

Heartiness (Kokumi)
aka continuity, mouthfulness, mouthfeel, and thickness.

Temperature
both cooking/freezing, and chemical heating/cooling caused by reactions with saliva.

I notice, though, that they don’t include “pop-rockiness”. That’s totally a taste too, damnitt!
Anonymous

Is it not a paradox to claim that people can “taste” the difference between the solutions, yet still maintain that both are “flavorless”?
Lady Katey

Timely, as I was just thinking about how luxurious 1% milk in my tea tastes after I got used to buying skim. I don’t think it’s necessarily about flavor- it’s more ‘mouth feel’.
randalll

I believe “spicy” isn’t technically a flavor because every taste receptor can pick up spiciness, there aren’t dedicated taste buds for it. That’s why really spicy food can overpower things you taste later on.

Also, why isn’t umami just called “savory”? Is it just because it sounds cooler?
- Albie
  
  “why isn’t umami just called “savory”? Is it just because it sounds cooler?”
  
  I think it is because the people who first identified it as a separate taste didn’t have “savory” in their vocabulary. The concept originated in Japan so it was first named in Japanese.
Anonymous

Americans only use three of the senses – Fat, Salt, and Sweet. At least that is what the food manufacturers think!
Anonymous

Fat offsetting bitterness is the reason young red wines taste so much better with foods with fat in them. It helps you taste the flavors over the tannins.
Anonymous

I wouldn’t be surprised if they find more that just 6 tastes. How about tasting “hot” in a “spicy” sense. Some people enjoy hot dishes more than others. People have a hard time thinking out-side-the-box especially when they are told there are “only” a certain number of things in a category.
- Anonymous
  
  Actually, spicy hot comes from the pain/pleasure centers. Some people like hot spicy stuff because it literally causes pain as the acids burn the palette and tongue. For people with a high tolerance for pain, the experience could be pleasurable. Myself, I don’t like my food to bite me back and I know that I have a low tolerance for pain.
  - IamInnocent
    
    Although there can be masochistic eaters, those with high tolerance for spicy food don’t experience pain because they stay below the threshold of pain. They are after taste, not (necessarily, not me at least) pain.
    - Antinous / Moderator
      
      Capsaicin addicts have substantially fewer hot receptors than the average person. They have to ingest a lot more to get the same effect.
- Grey Devil
  
  I agree with Spicyness being another flavor. Some argue that it isnt a true flavor because the spice hijacks the tongues receptors and causes the spicy taste, but i feel that spice adds a lot to the flavor to some foods.
thebelgianpanda

According to Herve This in Molecular Gastronomy, research has shown that even in the taste groups (bitter, sweet, etc) there are specific receptors for specific flavor molecules. For example, one of the studies he cites found there are quite a few different receptors for bitter flavors that all taste slightly different. So if you go by ‘# of receptors’ = ‘# of flavors’, then there are likely hundreds if not more.

Here is a bit more meat for the discussion :D
http://books.google.com/books?id=qO-e-JFViVYC&pg=PA100&lpg=PA100&dq=herve+this+bitter+flavors&source=bl&ots=ePcICTgrZd&sig=0MbxPpSFh4v9blXXYNmrL40Q7tg&hl=en&ei=D0GZS5KBPY_QtgP5g7nCAQ&sa=X&oi=book_result&ct=result&resnum=5&ved=0CBQQ6AEwBA#v=onepage&q=&f=false
Anonymous

“What that means is that somewhere there is water with chunks of fat in it, and I’ve got to get me some of that water because that is the tasty fucking water” – Lewis Black
wobblesthegoose

How is this different from Umami? Did researchers decide they needed to simplify it for Western audiences?
- Cheqyr
  
  Leave my mommy out of this.
- Anonymous
  
  Umami is definitely very different taste-wise than fat. Mushrooms are a prime example of the umami flavor but mushrooms on their own won’t have anything like a ‘fat’ taste.
  
  My question about this study would relate to texture and weight. Could people perhaps detect the different densities and textures and could this have played a role in their ability to accurately tell which foods contained a higher level of fat?
_OM_

…Like this is news. Dairy farms have known for decades that people can easily tell the difference between regular milk and the lo-fat crap just by the taste.
seyo

Glad that science has confirmed this, but it falls squarely in the NO FUCKING SHIT SHERLOCK category. Considering that fat is one of the three vital macronutrients and is essential to our survival, it would make sense that our sensory apparatus would be highly tuned to detect it.
cymk

I wouldn’t say fat itself has a flavor as in something desirable like the other 5 mentioned in the article. I would say fat (the triesters of glycerol and fatty acids) has the ability to bring out flavor in food; specifically meat and starches. Whether its called “umami” or “savory” it still makes certain types of food seemingly dance on the tongue with flavor.

From personal experience, when I have a nice juicy burger that hasn’t been completely stripped of fat, its fantastic same goes with the fries that have been deep fried in lard or oil; delicious. Conversely turkey burger, which generally contains little if no fat, is extremely bland and flavorless to me. Same goes for the “baked” not fried foods, they lack the flavor their fatty counterparts have.
shadowfirebird

I can personally attest to the truth of this.

I recently cut most of the fat out of my diet. I can now tell when I eat something that has more than a little fat. I’m not sure I’m tasting the fat, strictly speaking, but I know it is there.

Perhaps the best parallel is drinking coffee and knowing that it is not decafinated. Or drinking soda and knowing that it has sugar, not sweetener in it.
- demidan
  
  I have been able to know which is which when it comes to decafinated coffee and sugar free soda for a long time, and oddly it is not through taste it is through texture. While I have a very sensitive pallet for flavours, it is equally sensitive for textures, and decafinated coffee and sugar free soda are “thinner” than their cafinated and sugar rich counter parts.
  Fat is another interesting texture, in liquid form or warm it adds a layer of texture to what ever it is in. Things like chicken stock with emulsified fat are not only richer than fat free stock it feels heavier on the tongue.
  P.S. it is hard to describe such ephemeral tastes and textures, the feeling/taste/texture is often so short lived that one must repeatedly taste and sample. (Which can be fun!)
  - shadowfirebird
    
    Agreed. Fat also coats your mouth in a different way.
    
    I suspect that I may also be actually detecting the different reaction of my saliva to the fat — the digestion process does in fact start in the mouth, after all — but I certainly can’t prove it.
    
    On the other end of the impressiveness scale, maybe I’m subconsciously registering the tastes that tend to go with fatty food — butter, oil, etc.
    
    The truth is most likely to be a little of all of these.
    - demidan
      
      Have you noticed the differences between natural fats and artificial fats in your mouth? Such as the difference between real butter cream and butter cream made out of margarine, the butter coats less heavy while the margarine sheaths your entire mouth with nasty. All in all natural fats bring much more to the plate then artificial ones.
Anonymous

“Spicy” isn’t recognized as a flavor because it’s the body’s reaction to the capsaicin in the food. That’s not to mean that there aren’t hot peppers without flavor…but flavor and heat don’t necessarily go hand in hand. As Antinous said — some people are more sensitive to the heat levels than others, and others increase their tolerance (kill more heat receptors??)…but that doesn’t make it a flavor.

Similarly, I don’t doubt for a second that humans are able to detect the presence of fat…that’s why we tend to like food with a high fat content — it feels silky on the palate, and fat carries the fat-soluble flavor molecules, so high fat means silky texture and lots of flavor= the yum. (In the same vein, adding wine or vodka or liqueur to a dish frees the alcohol-soluble flavour compounds, which is why things cooked with a little booze usually have more depth of flavour…because there’s more flavour.)

BUT…just like capsaicin, I’m not sure I’m buying that fat is a flavour in and of itself. Doubt it? Go get yourself a spoonful of Crisco (vegetable shortening) or lard — take a big mouthful, then come back here after you quit gagging and tell me how much flavour it has. (Hint: not much.)

The fat carries the flavour, just as alcohol in a sauce or water in a stock (because there are water-soluble flavour compounds, too) — and it’s really easy to tell when something has a high fat content or not…but that doesn’t mean that the fat has flavour itself.

(and before anybody hyperventilates — adding liqueurs and wines adds flavour on two levels — there is flavour in the liqueur/liquor/wine itself…but the alcohol itself is what frees the alcohol-soluble compounds.)
Anonymous

@shadowfirebird
Yes I agree. I have recently cut out high fat and even meat from my diet and now I feel I can taste it (yum), although I have become more addicted to Vegemite.
EggyToast

Just like how the plural of anecdote isn’t data, one science report (in a low-impact journal) isn’t fact.

There is a significant amount of research into taste and “fat taste” is sexy because of the dietary implications, but there is far more research showing that humans can’t taste fat.

But you know what can taste fat? Rats! They love the stuff. And they love it because it smells rancid. Which is certainly something that humans can sense, although it more shows that olfaction still plays a large role in the overall taste sensation.

At least, this is what I’m told by my wife who is a PhD in sensory biology.
- cymk
  
  “…that olfaction still plays a large role in the overall taste sensation.”
  
  Isn’t that the whole idea behind pinching your nose closed when drinking something foul tasting? So that you don’t taste the foul drink/ barely taste it?
Anonymous

I can’t link, but there was an excellent article in The New Yorker a couple years back about taste. I had never even heard of umami until then.

“Hot/Spicy” is definitely different from taste (it affects pain receptors not taste buds) but is still an important part of how we PERCEIVE taste overall.

Interestingly, SMELL (of which there are 7, as opposed to the 5 (now 6) tastes) is a HUGE part of taste perception. People who lose their sense of smell through chemical accidents usually become emaciated; eating is simply no longer pleasurable.
Anonymous

of course fat has a flavour… it tastes like fat!
im a vegetarian and dont eat animal fat. i can tell by taste (and smell) when donuts, potato chips, etc are cooked in fat rather than vegetable oil