. . . the two noblest of things, which are sweetness and light. --Swift (The Battle of the Books)
Sensation. 1. A chemical sign received by sensors in the tongue, lips, and mouth. 2. In tandem with aroma cues, a component of the complex message we decode asflavor.
Usage: Taste cues--the basic messaging features of food products, recipes, and ethnic cuisines--are chemically blended in cooking. (N.B.: "Cuisine," from Latincoquere, to cook, derives from the Indo-European root pekw-, to cook, ripen [note the allusion to fruit; see FRUIT SUBSTITUTE].)
Anatomy. Our sense of taste is not as keen as our sense of smell (i.e., more molecules of a food product are required for taste than smell; coffee, e.g., smells richer than it tastes). Bumps on the tongue (papillae) house clusters of taste buds which contain as many as 50 receptor cells each. The receptors themselves (found also in our palate and pharynx) resemble primitive neuromasts on the outer skin of fish and amphibians (see TOUCH CUE, Evolution).
Media. According to an article in the New York Times, we are remarkably conservative about our taste for foods: ". . . most people eat the same limited assortment of foods over and over again" (Hall 1992:C1). "Breakfast seems to be the most predictable meal of the day. Even those who embrace the unfamiliar at lunch or dinner will eat the same breakfast for weeks, months or even years without ever feeling the urge to introduce a new ingredient" (Hall 1992:C1; see ENTERIC BRAIN and FEAR, Food, fear of).
Origin. Taste elaborated as a means for the earliest pre-vertebrate ancestors of Homo to find food (see ORIENTING REFLEX, Evolution).
Pharyngeal delight. Some peppery tastes are esteemed for stimulating the back of the throat. Tuscan olive oils, e.g., which are made from earlier harvested, greener olives, leave a peppery flavor in the pharynx, as do the best New Orleans gumbos. The "hot taste" of Tuscan oils, gumbos, and chili peppers is sensed, as a tactile irritant, by cranial nerve V (the trigeminal [see below, Trigeminal "taste"]), which also enjoys the carbonation of soda pop, the "coolness" of mint, and the alcoholic "bite" of martinis, margaritas, and wine.
Psychology. Our aversion to bitter tastes may be innate (Thorndike 1940).
Trigeminal "taste." 1. A third chemical sensor, working alongside smell and taste, is the trigeminal sense. Trigeminal (cranial V) nerve endings in the tongue and oral cavity sense, e.g., pungent chemicals given off by such "hot" spices as red chili pepper (capsaicin), black pepper (piperine), mustards and horseradish (isothiocyanates), and onions (diallyl sulfide). They also respond to "cool" spices, such as mint (menthol), and to the chemical "bite" or "sharpness" of ethyl alcohol in tequila and rum. In each of these cases, our trigeminal nerve endings respond to chemical irritants rather than to gustatory taste cues per se (which are sensed instead by the facial nerve [cranial VII]). Trigeminal "taste" is an important ingredient in many--perhaps in most--of the world's cuisines. (N.B.: Though human babies initially experience aversive reactions to pungency in food, by adulthood they have acquired a seemingly indispensable need for trigeminal stimulation at mealtime.) In beverages and food products, our trigeminal sense also craves mechanical (e.g., crunchiness and texture) and thermal stimulation (e.g., the heat and cold of coffee and cola). 2. The trigeminal sense of "taste" evolved as a pain warning system, to protect the tongue and oral cavity from potentially dangerous or toxic substances. Many plants--notably those we use as spices--have evolved "pain" messages to discourage organisms (e.g., snails, insects, and mammals) from eating their leaves, stems, fruit, and seeds (see SECONDARY PRODUCT). 3. Why humans crave trigeminal stimulation in foods, beverages, and oral-care products (e.g., in minty mouthwashes, toothpicks, and toothpastes) is still a mystery. It has been suggested that the capsaicin in chili peppers works to release opium-like substances which address the brain as pleasure cues. Perhaps we like the thrill of culinary danger (see HERBS & SPICES, Usage).
Neuro-notes I. We not only taste, but like or dislike the tastes of our food. From birth through childhood, e.g., we find sweet tastes pleasant and bitter tastes unpleasant(but as adults, we may learn to appreciate the bitter taste of coffee). The sweet taste of sucrose (the ingredient of table sugar), e.g., has a calming effect on infants, and reduces their reactions to pain. (N.B.: Sugar on a pacifier reduces crying and slows an upset baby's heart rate by 30 beats per minute (Blass 1992). Our enjoyment of salt is innate.
Neuro-notes II. Taste cues are conducted through cranial nerves VII, IX, and X to the gustatory nucleus, which projects to the thalamus. From the latter, neurons project a.to the cerebral cortex's gustatory region (Brodmann's area 3b), and b. to the insula. Like aroma cues, taste cues evoke strong emotions.
Neuro-notes III. Mirror neurons: Mirror neurons have been found in taste (gustatory) regions of the human brain: ". . . the insula has mirror neurons that both detect disgusting facial expressions and express disgust toward unpleasant food and smells." (Source: Ramachandran, V. S. (2011). The Tell-tale Brain: A Neuroscientist's Quest for What Makes Us Human (New York: W. W. Norton).)
Photo of a sliced Big Mac (December 19, 2009, 2:00 PM, at McDonald's, 2903 E. 29th Avenue, Spokane, Wash., 99223, USA [cut through with a plastic, serrated knife provided by the restaurant]) by Doreen K. Givens (copyright 2009)