Taste on the tongue

The faces of those present appeared like grotesque colored masks strong agitation alternating with paresis the head, body and extremities sometimes cold and numb a metallic taste on the tongue throat dry and shriveled a feeling of suffocation confusion alternating with a clear appreciation of the situation. 

Many attempts were made to explain what the acid taste was like. French scientist Lemery, from the 17th century, tried in a most unusual manner to explain the effect of acid through the idea of particles. Fie theorized that this invisible substance, which makes up the acidic taste, consists of moving spiky particles, which cause the acidic taste on the tongue [8]. 

The dotted lines show how many degrees of difference of force exist between the bodies they separate, as estimated by the taste on the tongue, bodies following one another immediately having one degree, which is very small. When two bodies are separated by a moist conductor of the second cla s ... 

The contraction of frogs, taste on the tongue, and the sensation of light in the eye are produced when (i) two different metals or conductors of the first class touch one another on one side or form a heterogeneous metallic arc, whilst their opposite ends touch or enclose between them a conductor of the second class which forms the other arc or (ii) with one metal and two different moist conductors, different liquid pairs being most active with different metals. 

Simultaneous stimulation of the tongue with the appHcation of different taste stimuli produces an interaction, modification, or blending of the stimuli in some instances but not in others. Warm and cold sensations are reported to act similarly on the tongue in two groups bitter, warm, and sweet and sour, cold, and salty (24). The theory of the specificity of the taste buds may be subject to modification (25). 

MSG is used to give a meaty, savory, or brothy taste to foods by stimulating the glutamate receptors on the tongue. There are glutamate receptors in other parts of the body, notably the brain, where glutamate is a neurotransmitter. 

Although some neural fibers respond to sweet-stimulus compounds placed on the tongue, others do not. This pattern of sensitivity is often a very complicated one. The fibers often respond to more than one, sometimes even to all, of the four taste modalities. Very rarely does a fiber respond specifically to only sweet or salty substances. Furthermore, other fibers may have an entirely different spectrum of sensitivities, and may respond strongly to one sweetener and very weakly to another. Pfaffmann reported how two fibers, one having one pattern of sensitivity to taste, and the other, a different pattern, can signal two different taste-qualities, even though... 

Food is taken into the buccal cavity, where it is masticated by the teeth and mixed with saliva from three pairs of salivary glands. It moistens the food and dissolves some molecules enabling them to interact with the taste receptors on the tongue. Saliva contains Na% Cl and HCOs ions and a protein, mucin, which is a component of mucus that lubricates the chewed food on its way down the oesophagus. The pH of saliva is about 7.8, which neutralises acid formed by bacteria in the mouth this protects tooth enamel... 

The detailed mechanism of its taste-inducing behavior is still unknown. It has been suggested that the miraculin molecule can change the structure of taste cells on the tongue. As a result, the sweet receptors are activated by acids, which are sour in general. This effect remains until the taste buds return to normal. 

Ice cream emulsion has a very characteristic degree of stability. The air bubbles should remain dispersed, but as soon it melts in the mouth, the emulsion should break. This leads to the sensation of taste, which is very essential to enjoy its specialness. The sensation of taste on the surface of the tongue is known to be related to molecular shape and physicochemical properties. As soon as these molecules are separated from the emulsion, the taste sensation is recorded in the brain. Therefore, the various components must stay in the same phase after the breakup of the emulsion. Emulsifiers that are generally used have low HLB values (for W/O), and have been found to have considerable effect on the structure of the ice cream. 

An experimental difficulty lies in the fact that there are only a few thousand taste buds in the tongue, with only 50-100 cells in a bud. They age rapidly, having a lifespan of only about ten days.924 There may be only 30,000-50,000 hard-to-isolate taste receptor cells on the tongue s surface.923 However, very recently published reports describe a large family of bitter and sweet receptors in mice and humans924-928 and in Drosophila.929 930 The sweet-sour receptors are thought to activate a G protein called gustducin,931/932 which plays a role similar to that of transducin in vision and... 

The characterisation of a fruit type or variety will be reflected in the flavour profile of its volatile components. Analytical techniques can produce an accurate peak profile using gas chromatography, but in simpler terms the sensory receptors of most individuals can quickly differentiate between fruit varieties. We have four basic taste senses, sometimes described as sweet, sour, acid and bitter, and these are identified by taste receptors situated mainly on the tongue. The key component of flavour differentiation, so-called top-notes and the like, is detected not so much by taste as by aroma in the nasal cavity. Thus, during the process of eating and drinking, the release of aroma volatiles can be identified and an assessment of their value arrived at. 

Cocaine and other local anesthetics abolish not only the sensation of pain, but other special sensations, if they are suitably applied. Here also there is some selection. In the skin, they paralyze first the vasoconstrictor reaction, then progressively the sensations of cold, warmth, touch, tickling, pressure, pain, and joint sense. In the nose, they abolish the olfactory sense. On the tongue, they destroy the taste for bitter substances but have less effect on sweet and sour taste and none on salty taste. When cocaine is applied to the appropriate nerves, it is found that the centrifugal vagus fibers are paralyzed before the centripetal, vasoconstrictor fibers before vasodilator, bronchial constrictors before the dilators, etc. (Sollmann, 1944). 

Figure 3. Location of some oral chemosensory receptor systems. Taste buds (schematic upper right) are found on specialized papillae on the tongue and scattered on the palate and posterior oral structures. Free nerve endings are found...

On tasting the narrow, horizontal segments of the area from the start to the solvent front in many thin—layer separations of pepper extracts, we have noticed that there is a component always coming above the piperine spot which has a tingling sensation on the tongue. This substance has not been identified, but could consist of isobutylamide-like compounds reported from other Piper species by Atal t al (38). 

Salty tastants act directly on Na+ channels in the PM of cells on the tongue surface. Direct passage of Na+ through these channels causes depolarization and thence signalling to the CNS. Much (but not all) salt taste perception is inhibited by the voltage-sensitive Na+ channel inhibitor amiloride (see Chapter 4) and evidently some salt perception also occurs via amiloride-insensitive channels. 

Succinylation substantially increases specific volume of soy and leaf proteins (12,37). The succinylated soy protein becomes very fluffy and the color becomes much lighter, changing from a tan to a chalk white as the extent of derivatization is increased (12,47). No odors nor flavors were imparted by the succinylation process. Succinylation improved the whiteness and dispersibility characteristics of soy protein making it suitable for incorporation into coffee whiteners (47). Succinylated soy proteins hydrate rapidly on the tongue,""taste clean, but slightly acidic. It is not known if derivatization facilitates the removal of off-flavors from modified proteins. 

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