Tongue, chemical composition

Taste is the sensation that results when taste buds in the tongue and throat convey information about the chemical composition of a soluble stimulus. 

Fig. 17.44 The chemical compositions of coarse tephra at different depths in the Byrd-Station core classify them as alkali-rich tra-chytes/phonolites. The points labeled 1 and 2 are volcanic rocks from Mt. Takahe and Mt. Sidley, respectively, in Marie Byrd Land. The chemical compositions of the fine tephra in the Byrd-Station core scatter widely and are not shown on this diagram. The tephra from South Pole, the Yamato Mountains, and Vostok Station are andesites that could have originated from volcanoes in the South Sandwich Islands (3 = Candlemas Island, 4 = Bellingshausen Island). Tephra from the Lewis Cliff ice tongue are composed of...

Next, Moromi is wrapped in a cloth and squeezed slowly for as long as 3 days. The squeezed raw soy sauce is heated up to a certain temperature. This is not only for sterilization but for standardizing aroma and color and increasing stability of soy sauce by stopping enzyme activity. This process is an important process of soy sauce production. After heating process, the soy sauce is checked by inspectors for not only chemical composition but also color, aroma, and taste by using their eyes, nose, and tongue. Inspected soy sauce is bottled in the elean room. 

Definition the electronic tongue is an analytical instrarment including an array of low-selective chemical sensors and appropriate pattern recognition tool, capable to recognize quantitative and qualitative compositions of simple and complex solutions . 

Rudnitskaya, A., Schmidtke, b. M., Delgadillo, b, begin. A., and ScoUary, G. (2009b). Study of the influence of micro-oxygenation and oak chip maceration on wine composition using an electronic tongue and chemical analysis. Anal. Chim. Acta 642(1-2), 235-245. 

Following the development of the electronic nose for gas analysis, the electronic tongue (an array of potentiometric chemical sensors) has been devised for the analysis of complex liquid samples. If properly configured and trained (calibrated), the electronic tongue is capable of recognizing the qualitative and quantitative composition of multicomponent solutions of different natures. The electronic tongue and electronic nose, in combination, can be used to predict the sensory characteristics and their relationship to the quality of, e.g., apple juices measured by a trained sensory panel and consumers. 

The e-tongue can be defined as an analytical instrument composed of an array of nons-elective chemical sensors with partial specificity to different solution components and an appropriate pattern recognition system, capable to recognize quantitative, and qualitative composition of simple and complex solutions. 

The main objective of electronic noses, and also electronic tongues (its analogues for the liquid phase), is to discriminate or differentiate samples of complex and unknown composition without needing to identify their individual chemical components. Hence, its objective contrasts completely with that of GC, where at least the most relevant components must be identified. As the objectives are different, so the results and information obtained will also be different and the evaluation of the methodologies is dependent on what practical information is being looked for. The more common situation in which e-noses are applied is to discriminate between products in the field of food, beverages, pharmacy, and perfumery and for safety and environmental conhol (Gardner and Bartlett, 1993,1999 Dickinson et al., 1998). 

Probably the most interesting study showing altered taste thresholds as a function of body state is that of Bradley (13). Perfusing the head of the rat with an artificial blood and simultaneously recording from the chorda tympani nerve, Bradley studied the interaction of the state of the body as reflected by the blood and the electrical response in the taste nerve. He concluded that the taste nerve has a dual nature, responding in different ways to chemicals applied on the tongue and to the composition of the blood, monitored by the intero-receptors. 

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