Taste, along with smell (olfaction) and trigeminal nerve stimulation (registering texture, pain, and temperature), determines flavors of food or other substances. Humans have taste receptors on taste buds (gustatory calyculi) and other areas including the upper surface of the tongue and the epiglottis.
The tongue is covered with thousands of small bumps called papillae, which are easily visible to the naked eye. Within each papilla are hundreds of taste buds. The exception to this is the filiform papillae that do not contain taste buds. There are between 2000 and 5000 taste buds that are located on the back and front of the tongue. Others are located on the roof, sides and back of the mouth, and in the throat. Each taste bud contains 50 to 100 taste receptor cells.
The sensation of taste can be categorized into five basic tastes: sweetness, sourness, saltiness, bitterness, and umami. Taste buds are able to differentiate among different tastes through detecting interaction with different molecules or ions. Sweet, umami, and bitter tastes are triggered by the binding of molecules to G protein-coupled receptors on the cell membranes of taste buds. Saltiness and sourness are perceived when alkali metal or hydrogen ions enter taste buds, respectively.
The basic tastes contribute only partially to the sensation and flavor of food in the mouth — other factors include smell, detected by the olfactory epithelium of the nose; texture, detected through a variety of mechanoreceptors, muscle nerves, etc.; temperature, detected by thermoreceptors; and "coolness" (such as of menthol) and "hotness" (pungency), through chemesthesis.
As taste senses both harmful and beneficial things, all basic tastes are classified as either aversive or appetitive, depending upon the effect the things they sense have on our bodies. Sweetness helps to identify energy-rich foods, while bitterness serves as a warning sign of poisons.
Taste perception fades with age: On average, people lose half their taste receptors by the time they turn 20. Not all animals can sense all tastes.
Basic tastes. Measuring relative tastes. Gustatory system. Further sensation. Other concepts. Disorders of taste. Beefy meaty peptide. Beefy meaty peptide, also known as delicious peptide and abbreviated as BMP, is an 8-amino acid long peptide that has been identified as giving a beefy flavour to foods in which it is present.
It was isolated from beef soup by Yamasaki and Maekawa. Sequence Lys-Gly-Asp-Glu-Glu-Ser-Leu-Ala References ^ Jump up to: a b Tamura, Masahiro; Nakatsuka, Tohru; Tada, Makoto; Kawasaki, Yoshihiro; Kikuchi, Eiichi; Okai, Hideo (1989). BitterDB. Summary Basic taste qualities like sour, salty, sweet, bitter and umami serve specific functions in identifying food components found in the diet of humans and animals, and are recognized by proteins in the oral cavity.
Recognition of bitter taste and aversion to it are thought to protect the organism against the ingestion of poisonous food compounds, which are often bitter. Bitter taste receptors are expressed not only in the mouth but also in extraoral tissues. BitterDB database, available at includes over 550 compounds that were reported to taste bitter to humans. The compounds can be searched by name, chemical structure, similarity to other bitter compounds, association with a particular human bitter taste receptor, and so on. Database Overview Bitter Compounds Search Examples of bitter compounds in BitterDB BitterDB currently contains more than 550 compounds that were cited in the literature as bitter.
Digital lollipop. A digital lollipop is an electronic device that synthesizes virtual tastes by stimulating the human tongue with electric currents.
The device is capable of producing the four primary tastes: sweet, sour, salty and bitter. Digital lollipops were developed through research led by Nimesha Ranasinghe at the National University of Singapore. Design According to Ranasinghe, "The system is capable of manipulating the properties of electric currents (magnitude, frequency, and polarity: inverse current) to formulate different stimuli. Currently, we are conducting experiments to analyze regional differences of the human tongue for electrical stimulation.
Palatability. Palatability is the hedonic reward provided by foods or fluids that are agreeable to the "palate" in regard to the homeostatic satisfaction of nutritional, water, or energy needs. The palatability of a food or fluid, unlike its flavor or taste, varies with the state of an individual: it is lower after consumption and higher when deprived.
Palatability of foods, however, can be learned. It has increasingly been appreciated that this can create a hedonic hunger that is independent of homeostatic needs. Brain mechanism Advertisement of Castor oil as a medicine by Scott & Bowne company, 19th century. Vomeronasal organ. The vomeronasal organ (VNO), or Jacobson's organ, is an auxiliary olfactory sense organ that is found in many animals.
It was discovered by Frederik Ruysch prior to 1732 and later by Ludwig Jacobson in 1813. This organ is the sense organ involved in the flehmen response in mammals. The VNO is the first stage of the accessory olfactory system and contains sensory neurons that detect chemical stimuli. The axons from these neurons project to the accessory olfactory bulb, which targets the amygdala and bed nucleus of the stria terminalis, which in turn project to the hypothalamus. The vomeronasal organ is mainly used to detect pheromones, chemical messengers that carry information between individuals of the same species. As with other olfactory systems, chemical messages are detected by their binding to G protein-coupled receptors. Structure Placement of Jacobson's organ in a snake.