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

Question

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

In: Chemistry

Answer 1

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.