What causes things to taste? What is in some foods that aren’t I others that make them taste different?


What causes things to taste? What is in some foods that aren’t I others that make them taste different?

In: Chemistry


Your tongue (and the lining of your nose) are covered with special chemical receptors. We call the ones on your tongue “taste buds” and the ones in your nose “smell receptors”. They’re both triggered by specific chemicals or families of chemicals. For example, the ones that are triggered by surgars (glucose, fructose, etc.) convey the taste of “sweet” to our brain.

Different foods taste different because they contain different chemicals, and different mixtures of chemicals, so they set off a different set of nerves to different degrees. Our brains squash all that information back together into “taste”.

A few chemicals work on other nerves…the most well known is capsaicin, which sets off your heat detecting nerves. It’s the active ingredient in chili peppers. That’s what makes “spicy” foods “hot” even though they’re not any different temperature than the rest of your food.

Essentially it’s just the function of the tongue, the tongue has receptors on it that only react to certain configurations of molecules. As everything is made of molecules in different configurations it’s going to trip different receptors. As our food sourcees aren’t all uniform matter, they will be made up of various combinations of matter triggering the different sets of taste receptors.

But then you can ask, “well, why do we have different taste receptors?” Science doesn’t really know why that evolved, they only know how that the ability to taste differences in food lets us detect the content of our food, poison tends to be bitter, evolutionary biologists think this taste sense was advantageous to our survival. Also lets us know what foods are nourishing, the foods that taste best to humans tend to be the most energy dense (not necessarily healthy by our new diet standards).

Up til now, science has said it is because of chemicals. However, the past few years now some scientists have been suggesting it is because of quantum vibrations (don’t ask, I don’t know either). They apparently started to consider this when they found out that almond and cyanide smelt the same despite having completely different chemical compositions.

Your cells of your taste buds are covered in molecules called receptors. When those receptors encounter a certain chemical, they inform the cell they’re attached to which in turn informs your brain of the presence of that chemical. Here’s what sets off your 5 basic taste receptors:

-Sweetness is triggered primarily by sugars and sugar-like molecules (i.e. sugar alcohols or aspartame).

-Sour is triggered by hydrogen ions (i.e. acidity)

-Salty is actually poorly understood but is thought to be a combination of sodium, chloride and several similar ions.

-Umami (i.e. savory) is triggered by glutamate, as in MSG or monosodium glutamate, and a few similar compounds.

-Bitter is the most broad sensation. In general bitterness evolved as an evolutionary defense mechanism to prevent us from eating poisonous or inedible things. As a result many compounds which are toxic or irritating to the digestive system and are common in nature trigger bitterness. Things with a relatively basic pH also tend to taste bitter to us for similar reasons.

You might notice that’s a small list of tastes and you’d be right – most of what most people call taste is more accurately called flavour and is a combination of taste and smell. What makes a lemon and a lime, for instance, so recognizably different despite both being very sour, slightly sweet and slightly bitter is their unique smells. When you eat just about anything you engage in a process called retronasal olfaction – essentially some of the air in your mouth makes its way up to your sinuses where you smell whatever’s in your mouth. Humans have thousands and thousands of types of smell receptors and most recognizable smells are actually a combination of many different receptors being set off by many different smell molecules at once. Because of that the most accurate answer to your question is some combination of molecules which are unique to the food you’re tasting.