People often use the terms taste and flavor interchangeably. Scientists do not. Flavor is a complicated mix of sensory data. Taste is just one of the senses that contributes to flavor.
Here’s how it works: As you chew, your food releases molecules that begin to dissolve in your saliva. While still in the mouth, these food molecules contact bumpy papillae (Puh-PIL-ay) on your tongue. These bumps are covered with taste buds. Openings in those taste buds, called pores, allow the tasty molecules to enter.
Once inside the taste pores, those chemicals make their way to specialized cells. These cells sense tastes. Taste cells have features on the outside known as receptors. Different chemicals fit into different receptors, almost like a key into a lock. The human tongue has 25 different types of receptors to identify various chemicals that are bitter. Just a single receptor type unlocks the sense of sweetness. But that sweet receptor “has many pockets, like one of those toys that has slots you can fit a square or triangular block into,” explains Danielle Reed. She’s a geneticist at the Monell Chemical Senses Center in Philadelphia, Pa. Each of those slots, she explains, responds to a different type of sweet molecule. For example, some respond to natural sugars. Others respond to artificial sweeteners.
But those tastes sensed by the tongue are only a part of what we experience as flavor.
Think about biting down on a just-picked peach. It feels soft and warm from the sun. As its juices flow, they release odor molecules that you smell. These odors mingle with the fruit’s taste and that soft, warm feel. Together, they give you the complex sense of a sweet peach — and let you tell the difference between it and a sweet blueberry. (Or between a bitter Brussels sprout and a bitter turnip.) Flavor, then, is that complex assessment of a food or beverage that develops when our brain melds together data from our different senses.
Taste and flavor together influence how people experience food. Why do we need both? “Taste is a nutrient detector and a toxin avoider” that we’re born with, explains Dana Small. She’s a clinical psychologist at Yale University in New Haven, Conn. Sweet or fatty foods are calorie rich. Those are welcoming tastes when someone is hungry. Bitter warns that some food may be poisonous. From birth, she explains, the body is wired to recognize such taste-based messages.
artificial sweetener A chemical substance that has a sweet taste but few or no calories. People and food manufacturers add artificial sweeteners to foods and drinks to give them a sweeter taste. Many different artificial sweeteners exist. They include saccharin, sucralose and aspartame, among others.
cell The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.
chemical A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H2O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.
clinical (in medicine) A term that refers to diagnoses, treatments or experiments involving people.
dissolve To turn a solid into a liquid and disperse it into that starting liquid. (For instance, sugar or salt crystals, which are solids, will dissolve into water. Now the crystals are gone and the solution is a fully dispersed mix of the liquid form of the sugar or salt in water.)
flavor The particular mix of sensations that help people recognize something that has passed through the mouth. This is based largely on how a food or drink is sensed by cells in the mouth. It also can be influenced, to some extent, by its smell, look or texture.
meld A verb meaning to fully blend or merge together (as when two fatty solids are melted and then stirred until fully mixed in a pot).
molecule An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).
nutrient A vitamin, mineral, fat, carbohydrate or protein that a plant, animal or other organism requires as part of its food in order to survive.
papillae (sing. papilla) In biology, these are small round projections, or protuberances, from a surface. They range from pimples on the skin to bumps at the root of a hair or feather. The best known are those bumps on the tongue that host taste buds.
pore A tiny hole in a surface. On the skin, substances such as oil, water and sweat pass through these openings.
psychologist A scientist or mental-health professional who studies the human mind, especially in relation to actions and behaviors.
receptor (in biology) A molecule in cells that serves as a docking station for another molecule. That second molecule can turn on some special activity by the cell.
taste One of the basic properties the body uses to sense its environment, especially foods, using receptors (taste buds) on the tongue (and some other organs).
taste buds A collection of 50 to 100 or so taste receptors. They’re found on the tongues of land animals. When certain chemicals in food or other materials trigger a response in these receptors, the brain detects one or more of five types of tastes —sweet, sour, salty, bitter or umami.
toxin A poison produced by living organisms, such as germs, bees, spiders, poison ivy and snakes.