certain compounds were responsible for different tastes

Gallin

I was wondering if certain compounds were responsible for different tastes. Like a certain one for bitter ,salty, sweet, and sour. Thanks for any info you can provide.

alxm

Well, yes. But the traditional sweet/salty/sour/bitter groupings are pretty loose. I'm a bit doubtful about how well-supported they are by actual science. But that's a question for a biologist.

Anyway, the way it works in general is that you have lots of receptors in your mouth; special enzymes that trigger some signal to your brain when specific molecules bind to them. The size, shape and chemical properties of a molecule is what determines if it binds to a receptor or not. A simplified picture is this; basically the enzyme has a shape that 'fits' the molecules that are supposed to bind to it.

Some of the receptors in your body are specific to single compounds, but your taste receptors can react to many of them. All molecules that have some chemical feature that 'fits the lock' will trigger the corresponding taste. So you have for instance artificial sweeteners that trigger the same receptors as sugar, but trigger a much stronger signal, so only a small amount of sweetener will give the same response as a much larger amount of sugar.

Capsaicin, the substance that makes hot peppers 'hot', really does taste 'hot' - it actually triggers not only taste receptors, but heat receptors in your mouth.

So, there are very many chemical compounds that have taste, and most of them have somewhat different tastes, because they trigger different combinations of receptors. (and to different extents, it's not quite an on/off thing, as far as I know) But it's hard to attribute the taste of most of our foods to any single chemical compound. There are usually thousands of compounds involved.

Usually, artificial flavors are made up of only a handful of compounds that have been identified as the biggest contributors to the taste. For instance esters, when it comes to fruits. That's why artificial flavors have a bad name- they don't have all the compounds in them, so the taste is not as 'rich'.

nismaratwork

I'd add, there are crossovers and enhancing "tastes" such as sodium, glutamates, and capsaicin (as mentioned). I'd add... beyond the basics, you need smell to make the most of this and achieve "taste" beyond bitter(Base), sweet(Sugars), salty(Na, K), sour(Acid), 'Umami' (Glutamate), and heat (Capsaicin).

Anosmia will cause what you recognize as taste to be reduced to those simple factors, so it's not that clear just how the whole system works.

On thing that IS clear, is that the "tongue model" in which there are clearly demarcated region of the tongue is patently false.

Then, you have non-taste responses to something overly caustic, alkalai, acid, etc.


If you think about it: "heat" is something that is a defense for plants, and a lure to some animals such as birds that lack the necessary receptors. They LITERALLY don't experience a berry that we'd find bitter, as bitter... they lack that recepter group, so there is no place for those molecules to activate a nervous reaction.

It's pretty similar to the action of SSRI's trying to "fit" a given receptor... same principle. As for the evolutionof this; why is bitter generally unpleasant?... usually it's poisonous to us. Why do we crave salt?... we need it... a lot. Why is sweet so pleasant?... it's our fuel.

Gallin

So you couldn't recreate the taste of say a hamburger just from a couple of chemicals?

nismaratwork

No, but you can approximate some of the tastes... ususally in a dozen or so chemicals. In the case of a burger, take this real world example:

McDonalds used to fry their french fries in Lard (specifically rendered beef fat), but when they changed to oil... they changed their flavor profile! Now, they went to a company in New Jersey which made an additive to their frying medium which imparts a similar taste.

So, the aim there is not a burger, just some of the "high notes"... which is usually the case. However, that means you lose depth of flavor, and the approximations are more difficult the more complex the original.

Lievo

Depends what you call taste. In a very restrictive sense, this all comes from 4 types of receptors within the tongue. In a more common sense such as the taste of an hamburger, then most of the taste is in fact carried by olfaction. Then you'll have also a contribution of nociceptors (capsaicin and gazeous liquids), proprioceptors (consistence of the food), expectations (coca lovers that prefer it over pepsi, but if it's in a pepsi can), vision, and emotionnal memories (the taste of wiskey is not the same when you had a bad experience with it, as you may have noticed yourself). An example for vision is the fact that kids prefer their lunch, whatever the lunch, when it's in an McDo box.

PS: it'd have fit better in the biology forum I think
PPS also cutaneous receptors in the form of hot and cold receptors

Gallin

So if there are basic tastes are there basic odors? If so are they also controlled by certain chemicals.

Lievo

Both are about chemical properties, but the situation is far more complex for odors than for taste. Basic tastes are tied to one type of receptors. Everything is clear cut, no pb. One can also define some basic odors, but that's a bit artificial and the link to the chemical properties is a mess. There is hundreds if not thousands of chemical that can bind to odorant binding proteins, so an odor is any recipe (combinaison of some of these chemicals in different proportion) that evokes about the same pattern of activity in the olfactory epithelium.

nismaratwork

Odors are FAR more numerous... faaaaaar more numerous. We're designed to scent a huge number of molecules (although, nowhere near as many as a dog).

Gallin

So it would be possible to combine enough stuff together to make something taste and smell like a hamburger when it is not a hamburger? ( hamburger is just an example but other foods as well )

nismaratwork

It's currently beyond the reach of modern "flavor" science, but in theory there should be no reason that it isn't possible. In fact, I'd say the trend is towards greater fidelity in artificial flavors, but nowhere near matching the taste in every aspect from texture to scent and basic tastes.

So, yes... possible, but not anytime really soon.