Ask A Scientist
How do we taste certain foods?
Asked by: Lily Combs
School: St. John the Evangelist School, Binghamton
Teacher: Anu Rai
Hobbies/Interests: Acting, playing piano, drawing, singing, reading, shopping, talking, cooking, sports and arts and crafts.
Career Interest: Baker, actress, fashion designer, horse trainer, veterinarian, artist or teacher.
Answer from Kyle Reeser
Biomedical Engineering Graduate Student, Binghamton University
Research area: Magnetic stimulation of taste
Interests/hobbies: Traveling, language studies, cooking and music
In everyday English, we use the terms “taste” and “flavor” synonymously. The sense of taste, though, contributes only partially to your overall food experience; it is the ability to identify the sweet, salty, bitter, sour, and savory characteristics of the food and drink we consume. Evolution has selected for the ability to detect these taste qualities. On a cellular level, we have an absolute need for sugar, and so it has been very important to be able to seek out these often high-energy foods. The perceived saltiness of food indicates the presence of certain elements (typically sodium and chlorine) that are necessary for cellular function. Many naturally occurring bitter compounds are toxic if ingested, and therefore our perception of this taste is the most sensitive, and traditionally aversive. However, humans do often ‘acquire a taste’ for such bitter substances as coffee, tea, and the quinine in tonic water. A sour taste is how we recognize acidity in our food. Sourness has been historically avoided as it might indicate a spoiled or unripe meal. Finally, savory is a gratifying quality associated with the ingestion of glutamate—for example, bacon drives our taste buds wild!
Flavor, on the other hand, is the full experience of your meal: its taste, texture, temperature, spiciness, and especially smell. As you chew, you are forcing air from your mouth through your nasal passages, carrying the food’s scent along with it. Without these interconnected senses we would not have the ability to appreciate the complex flavors of our meal. Loss of smell due to sickness or age can make mealtime a chore rather than a pleasure. Try plugging your nose while eating your favorite snack—is it an apple or wet cardboard?
There are an average of 5,000 taste buds in the mouth, with many found on the surfaces of the small bumps visible on the tongue, called papillae (puh-pill-ee). Taste buds send electrical signals to the brain regarding the type and amount of substance you are eating.
Contrary to conventional wisdom, perceptions of different tastes are not designated to specific areas of the tongue. The taste maps we know and love from textbooks are an oversimplification in that all portions of the tongue can in fact detect each of the five basic tastes, to a varying degree.