Science Biweekly

BETHESDA, MD - Savory wine and sapid beer all vary in the taste from bottle to bottle. The variety of flavor is attributed to the sensor cells found in taste buds spread throughout your tongue, which recognize 5 basic tastes: sweet, sour, salty, bitter and savory. The flavors that our brains recognize are a combination of taste, smell, temperature, and texture. This combination generates our perception of how a hamburger tastes and evolved with our survival instinct to avoid potentially poisonous foods. To understand how taste is perceived, it’s important to understand the biology of taste buds (PubMed, 2016).

Taste buds are located in sub-mucous membrane papillae primarily on the tongue, however, papillae are also located in the throat and elsewhere in the oral cavity. An average person contains 2,000 to 4,000 taste buds within their oral cavity. The majority of our taste buds are located on the edges of the tongue and are equally distributed. Interestingly, there are clusters of bitter specific taste buds located at the back of your tongue. Evolution has selected for this organization as a last effort to avoid swallowing a poisonous substance.

Taste buds contain two types of sensory cells: broad or specific. Broad sensory cells are able to respond to molecular compounds of all 5 tastes but vary in their sensitivity. Specific sensory cells are important for responding to the strength of a taste. The combination of broad and specific sensory cells’ messages are computed in the brain to our perception of taste.

Our favorite molecule capsaicin (the molecule responsible for the heat in chili peppers) does not have a taste receptor. Instead, capsaicin binds to the sensory neurons that detect pain and temperature. The molecule triggers the receptors to generate a heat related response that results in a fiery mouth.

Similar to the graying of hair, our sense of taste changes as we age. When we are young we have more taste buds than a grown adult. Infants generally explore the world with their mouth and the abundance of taste buds likely help infants perceive the world. As children, we are able to detect sweet and salty foods at a greater intensity driving us to devour grandma’s cookies before and after dinner. When we are roughly 50 years old, changes in our sensory neurons for taste and smell start to affect our ability to detect varieties and intensity of flavor (Schiffman, 1993). The atrophy of our sensory cells due to age occurs gradually and is usually not recognized.

The number of flavors we're able to perceive is truly endless. With the complexity of our palate we should all make it a goal to try different foods and enjoy the culinary art. Similar to art we view at museums, we will dislike some dishes but become enticed by others. The next time you see jing leed on the menu, give it a try and see how you perceive the flavor.

Citations:

Schiffman, S. S. (1993). Perception of taste and smell in elderly persons. Critical Reviews in Food Science & Nutrition, 33(1), 17-26.

How does our sense of taste work? (2016). PubMed website: https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072592/