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.