Taste, sour

Table 2 Hsts examples of compounds with taste and their associated sensory quaUties. Sour taste is primarily produced by the presence of hydrogen ion slightly modified by the types of anions present in the solution, eg, acetic acid is more sour than citric acid at the same pH or molar concentration (43). Saltiness is due to the salts of alkaU metals, the most common of which is sodium chloride. However, salts such as cesium chloride and potassium iodide are bitter potassium bromide has a mixed taste, ie, salty and bitter (44). Thus saltiness, like sourness, is modified by the presence of different anions but is a direct result of a small number of cations.

Only acids are sour. Sourness is not identical to chemical acidity or pH, which is a function of the hydrogen ion concentration, but also appears to be a function of the entire acid molecule. A combination of pH and acid concentration determines the actual degree of the sour taste. At the same pH, any organic acid, eg, citric acid, exhibits a far greater sourness than a mineral acid, eg, hydrochloric acid (27,28). 

Examples include hydrochloric acid, nitric acid, and sulphuric acid. These are strong acids which are almost completely dissociated in water. Weak acids, such as hydrogen sulphide, are poorly dissociated producing low concentrations of hydrogen ions. Acids tend to be coiTosive with a sharp, sour taste and turn litmus paper red they give distinctive colour changes with other indicators. Acids dissolve metals such as copper and liberate hydrogen gas. They also react with carbonates to liberate carbon dioxide ... 

The compound that gives vinegar its sour taste is acetic acid, which contains the elements carbon, hydrogen, and oxygen. When 5.00 g of acetic acid are burned in air, 7.33 g of C02 and 3.00 g of water are obtained. What is the simplest formula of acetic acid ... 

Vinegar. Vinegar gets its sour taste from acetic acid. 

You are probably familiar with a variety of aqueous solutions that are either acidic or basic (Figure 4.6). Acidic solutions have a sour taste and affect the color of certain organic dyes known as acid-base indicators. For example, litmus turns from blue to red in acidic solution. Basic solutions have a slippery feeling and change the colors of indicators (e.g., red to blue for litmus). 

Taste. The dilute, aqueous solutions of each compound are sour tasting. ... 

Sensory receptors expressed in particular in taste receptor cells of the taste buds that sense the five basic tastes salt, sour, sweet, bitter and umami (glutamate taste). Sodium type ion channels sense salty taste whereas sour taste is transduced by potassium type ion channels. The underlying cause of sweet, bitter, and umami tastes is the selective activation of different groups of G protein coupled receptors that discriminate between sweet, bitter, and umami tasting molecules. 

Acetic acid, in the form of vinegar, is used to preserve foods such as pickles. It also provides the sour taste for salad dressings and mayonnaise. 

Lactic acid is what gives the sour taste to spoiled milk and to sauerkraut. It is used in foods to add tartness, and to preserve freshness in... 

Flavorings can be derived from simple acids that add a sour taste to foods, or they can comprise more complex molecules, such as dena-tonium benzoate, which is added to products to make them so bitter that no one will accidentally ingest harmful amounts. 

Carboxylic acids with one acid group are known as monobasic acids while those with two acid groups are dibasic acids. All acids with more than one acid group are in the class of polybasic acids. The simplest organic acid, formic acid, is responsible for the irritation of bee and ant stings. Vinegar is a 5% solution of acetic acid in water. The acetic acid is responsible for the characteristic sour taste. Citric acid, found in citrus fruits and used in soft drinks, is a tribasic acid with three carboxylic acid groups. The dibasic acid, adipic acid, is a major component of nylon. 

Boyle (1661) attempted to provide a more definite concept and attributed the sour taste of acids to sharp-edged acid particles. Lemery, another supporter of the corpuscular theory of chemistry, had similar views and considered that acid-base reactions were the result of the penetration of sharp acid particles into porous bases (Walden, 1929 Finston Rychtman, 1982). However, the first widely accepted theory was that of Lavoisier who in 1 111 pronounced that oxygen was the universal acidifying principle (Crosland, 1973 Walden, 1929 Day Selbin, 1969 Finston Rychtman, 1982). An acid was defined as a compound of oxygen with a non-metal. 

An acid is classically known as a substance whose aqueous solution (i) turns blue litmus red (ii) neutralizes bases (iii) reacts with active metals with the evolution of hydrogen and (iv) possesses a sour taste. A base is again classically known as a substance which in aqueous solution (i) turns red litmus blue (ii) neutralizes acids (iii) tastes offensive and (iv) gives a soapy feel. These given descriptions of acids and bases may also be regarded as being operational or or experimental definitions. 

A 42-year-old man with a history of diabetes and hypertension presents complaining of "heartburn." He reports a burning sensation in his upper chest and some regurgitation of sour-tasting material into his throat. The symptoms began about... 

Acids and bases are determined by their properties. The word acid comes from the Latin word acidus, which means sour. For example, lemon juice tastes sour because it contains citric acid. Sauerkraut, another sour-tasting food, is cabbage fermented in lactic acid. In fact, sauer (pronounced almost exactly like the English word sour) in German means acid. Sour cream also has lactic acid in it. 

Sour natural gas, 23 597 Sour syngas defined, 6 829 Sour taste, 11 566 South Africa, platinum-group metal deposits in, 19 604, 612 South African gold mines, 12 686 South African manganese mining, 15 555 South America... 

Acid Substance which increases the acidity of a foodstuff and/or imparts a sour taste to it... 

Clear, colorless, corrosive liquid with a strong vinegar-like odor and very sour taste. Odor threshold concentrations of 1.0 ppmv and 6.0 ppby were reported by Leonardos et al. (1969) and Nagata and Takeuchi (1990), respectively. Shaw et al. (1970) reported a taste threshold in water of 100 ppm. 

Antiglaucoma Ophthsusp 1% (10,15 One drop tid. Bitter or sour taste, blurred vision. 

There was no sign of my supernatural feline helper out in the calle. Feeling soiled and with a sour taste in my mouth, I hurried back through the dark to the watersteps where Giorgio was waiting. If I had just thrown away fifty ducats, Nostradamus would skin me. 

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