Tartaric acid, wine

The separation of a racemic mixture into its enantiomeric components is termed resolution The first resolution that of tartaric acid was carried out by Louis Pasteur m 1848 Tartaric acid IS a byproduct of wine making and is almost always found as its dextrorotatory 2R 3R stereoisomer shown here m a perspective drawing and m a Fischer projection... 

Tartaric acid [526-83-0] (2,3-dihydroxybutanedioic acid, 2,3-dihydroxysuccinic acid), C H O, is a dihydroxy dicarboxyhc acid with two chiral centers. It exists as the dextro- and levorotatory acid the meso form (which is inactive owing to internal compensation), and the racemic mixture (which is commonly known as racemic acid). The commercial product in the United States is the natural, dextrorotatory form, (R-R, R )-tartaric acid (L(+)-tartaric acid) [87-69-4]. This enantiomer occurs in grapes as its acid potassium salt (cream of tartar). In the fermentation of wine (qv), this salt forms deposits in the vats free crystallized tartaric acid was first obtained from such fermentation residues by Scheele in 1769. 

Occurrence. (R-R, R )-Tartaric acid occurs in the juice of the grape and in a few other fmits and plants. It is not as widely distributed as citric acid or S(—)-mahc acid. The only commercial source is the residues from the wine industry. (i -R, R -Tartaric acid has been found in the fmit and leaves of BauMma reticulata, a tree native to MaU (western Africa). Like the dextrorotatory acid, it forms anhydrous monoclinic crystals. 

Wine Making. Wine making is one of the principal areas of tartaric acid use. There is a relationship between the size of the grape crop and its tartaric acid content when grapes are pressed. In poor harvest years, the tartaric acid content is low in good harvest years, the tartaric acid content is high. Thus, in poor harvest years, tartaric acid often is added to correct acid deficiencies in wine. 

The acid potassium or calcium tartrates are found in many plants but the chief source of tartaric acid is the impuie acid potassium salt, which separates out as wine-lees, or argol from grape-juice in process of fermentation. 

Wein-saure, /. tartaric acid acidity of wine, -schone, /. fining for wine, -sprit, m. spirit of wine, (ethyl) alcohol, -starkemesser, m. wine hydrometer, enometer. -stein, m. tartar. — roher —, crude tartar, wine stone, argol. — gereinigter. —, purified tartar, cream of tartar. 

Little was done after Biot s discovery of optical activity until 1848, when Louis Pasteur began work on a study of crystalline tartaric acid salts derived from wine. On crystallizing a concentrated solution of sodium ammonium tartrate below... 

A substance made from the tartaric acid found at the bottom of this wine vat catalyzes enantioselective reactions. 

Tartaric acid is the molecule that makes unripe grapes taste sour. It is a principal flavor element in wine. 

Carboxylic acids present no exceptional problems in reversed phase analysis, although detectability may be a limitation in the analysis of simple fatty acids. Wine acids, including succinic, acetic, citric, lactic, malic, and tartaric,... 

Grapes are one of the few fruit crops that contain a significant amount of the weak organic acid known as tartaric acid, HOOC-(CHOH)2-COOH. More than half of the acid content of wine is ascribed to tartaric acid. As a weak acid, tartaric acid partially ionizes in water to yield the bitartrate or hydrogen tartrate ion ... 

Ascorbic acid/tartaric acid rn 5,(bipyridyl)ruthenium(II)-Ce(IV) 0.05-1.7/1.4-140 4.8/1.7 The method was applied to wine samples 66... 

As the story goes, a wine production batch gone bad provided fairly large amounts of a new organic compound, the study of which was deemed of practical importance for the French wine industry. The new material had the same molecular formula as tartaric acid, which to some experts of the time meant it had to be the same as tartaric acid. Solutions of salts of the new material, however, did not rotate the plane of polarization of plane-polarized light, as solutions of salts of tartaric acid were known to do. The new material was named para tartaric acid, or racemic acid (the name racemic acid being derived from the Latin racemus bunch of grapes). 

Natural compounds are also applied as chiral ligands in enantioselective homogeneous metallo-catalysts. A classical example is the Sharpless epoxidation of primary allylic alcohols with tert-butyl hydroperoxide [37]. Here the diethyl ester of natural (R,R)-(+)-tartaric acid (a by-product of wine manufacture) is used as bi-dentate ligand of the Ti(iv) center. The enantiomeric excess is >90%. The addition of zeolite KA or NaA is essential [38], bringing about adsorption of traces of water and - by cation exchange - some ionization of the hydroperoxide. 

Figure 4.7 Anion exchange separation of carboxylic acids in red wine. Column, Shodex C811, 100 cm x 7.6 mm i.d. eluent, 3 mM perchloric acid flow rate, 0.9 ml min-1 temperature, 60 °C detection, reaction detection using chloro-phenol red at 430 nm. Peaks 1, citric acid 2, tartaric acid 3, malic acid 4, succinic acid 5, lactic acid 6, formic acid and 1, acetic acid.

Scientists have debated about what type of wine Egyptians drank. Two major classes of wine are red and white (the distinction being in the type of grape, and whether the skin is also used) archaeological chemists have found residues scraped from ancient jars that contain tartaric acid, which is common only in grapes, but have generally been unable to determine the type of wine. 

Oxidation is another important factor for the wine-aging process. Major oxidation reactions taking place in wine following oxygen exposure actually involve other wine constituents that are primarily ethanol and, in the presence of metal ions, tartaric acid rather than flavonoids, although phenolic compounds have been shown to participate in oxidation of ethanol to acetaldehyde. ... 

In another work, Parra and coworkers proposed a method based on chemically modified voltammetric electrodes for the identification of adulterations made in wine samples, by addition of a number of forbidden adulterants frequently used in the wine industry to improve the organoleptic characteristics of wines, like, for example, tartaric acid, tannic acid, sucrose, and acetaldehyde (Parra et ah, 2006b). The patterns identified via PCA allowed an efficient detection of the wine samples that had been artificially modified. In the same study, PLS regression was applied for a quantitative prediction of the substances added. Model performances were evaluated by means of a cross-validation procedure. 

Vitis amurensis Rupr. V. vinifera L. Shan Pu Tao (Wine grape) (leaf, fruit) Malic acid, tartaric acid, racemic acid, oxalic acid.50 For abortion, cholera, dropsy, nausea. 

However, in view of quantities consumed by other populations, wines could make a significant contribution for tartaric acid conjugates and grapes and grape juice for caftaric acid, respectively. Lettuce is the major source of chicoric (dicaffeoyltartaric) and caffeoylmalic acid (up to 3 mg/100 g), but endive may have twice the concentration. Spinach is almost certainly the richest source of conjugated p-coumaric acid at some 30-35 mg/100 g [18]. 

Louis Pasteur encountered the phenomenon of optical activity in 1843, during his investigation of the crystalline sediment that accumulated in wine casks (a form of tartaric acid called paratartaric acid—also called racemic acid, from Latin racemus,... 

Whan rod wines lose color on the Continent they are said to be rancio, rusty in England tawny,- The coloring matter deepens on the deposit of tartar, and the tewny hue arises from age. Heat, too, will injure the color, which is thus not necessary to the flavor of the wine, being no way dependent upon it. Carbonate of potsssa, sometimes formed in wine, injures both the color and.flavor. It arises from the decomposition of the tartar, and in France is called the Urmre. A little tartaric acid being added, tho potassa forms cream of tartar, depositing crystals. 

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