Tartaric Acids

Tartaric Acids

 

dihydroxysuccinic acids, dibasic organic acids, HOOCCH(OH)—CH(OH)COOH, with two asymmetric carbon atoms in the molecule. All the theoretically possible tartaric acids are known: D-tartaric acid (I), solutions of which rotate the plane of polarized light to the right; its optical antipode, L-tartaric acid (II); D,L-tartaric acid (a

racemic mixture of D- and L-tartaric acids); and mesotartaric acid (III), which is optically inactive because of intramolecular compensation of the rotation of the plane of polarization owing to the presence of an additional axis of symmetry (ab).

The most important tartaric acid is D-tartaric acid (ordinary tartaric acid), which is present either in the free state or in the form of salts in many fruits, particularly grapes. When grape juice is fermented, the poorly soluble acidic potassium salt of tartaric acid, so-called cream of tartar, is precipitated. D-tartaric acid is obtained by the action of inorganic acids on cream of tartar.

D-tartaric acid and its salts (tartrates) are used extensively in the food industry (for example, in the preparation of soft drinks and in baking), in medicine (tartar emetic), in dyeing, in organic synthesis, and in analytical chemistry. In an alkaline medium, D-tartaric acid dissolves Cu(OH)2, yielding a transparent bright blue solution—Fehling solution—that is used as a reagent in testing the reducing capacity of substances.

V. N. FROSIN

References in periodicals archive ?
The highest values of complexes formed were observed in acetic acid, followed by malic, citric and tartaric acids (Figures 1A and B).
* Greater degradation of L-malic and tartaric acids, resulting in a decrease in total acidity.
The bubbles erode enamel, due to a high concentration of phosphoric, malic, citric and tartaric acids." Drink through a straw to minimise damage, he advises.
After neutralization, the values recorded were less than or equal to 5 for only the first three test doses (2.5% to 0.625%), in the case of citric, lactic, and tartaric acids, whereas these values were greater than or equal to 6 for the other doses (0.312% to 0.0198%).
All culture media were purchased from Oxoid, UK.Acid standards for citric acid, oxalic acid, malic acid and tartaric acids were attained from Sigma-Aldrich Co.
"In practice, the upgrade involved re-lining some of the tanks, renewing electrical systems, increasing the number of sensors needed for documentation and filtering the sulphuric and tartaric acids using UV lights to prevent the formation of algae."
The vinegar has malic and tartaric acids that quicken digestion and help break down fats and proteins.
IFP's Non-PHO encapsulated ingredients include, but are not limited to, encapsulated minerals and acidulants such as salt, citric, fumaric, malic and tartaric acids, encapsulated nutraceuticals such as caffeine, and ascorbic acid and encapsulated sodium bicarbonate.
plantarum by centrifuging and resuspending cultures in either weak organic acid buffers, such as citric, lactic or tartaric acids, or in strong mineral acid solutions, such as hydrochloric or sulfuric acid solutions.
plantarum was studied by centrifuging and resuspending cultures in either weak organic acid buffers, such as citric, lactic or tartaric acids, or in strong mineral acid solutions, such as hydrochloric or sulfuric acid solutions.
The following objectives were therefore chosen for the current investigation: to study the kinetics of potassium (K) and silicon (Si) release from partially humus-free clay and clay-humus complex by tartaric acid; to study structural changes in humus-free clay and clay--organic complex by X-ray diffraction after extraction by tartaric acids
The stability constants of Ca and Mg tartaric acids Mg (log [[beta].sup.T.sub.MgT] = 1.91; log [[beta].sup.T.sub.CaT] = 2.17; log [[beta].sup.HT.sub.MgHT] = 0.92; log [[beta].sup.HT.sub.CaHT] = 1.11) measured at I = 0.09 M and I = 0.2 = M, respectively, were corrected by the Debye-Huckel equation [12].