Gluconic acid

• Dextronsäure
• (2R, 3S, 4R, 5R) -2,3,4,5,6 - pentahydroxyhexanoic

Syrupy liquid crystalline in the pure state

Fixed

1.24 g · cm -3

131 ° C.

417 ° C

Soluble in water, poor in ethanol and ether

Attention

Template: Infobox chemical / molecular formula search available

D- gluconic acid is a carboxylic acid selected from the group consisting of fruit acids. In the scheme of carbohydrate-derived compounds it is assigned the group of onic acids. Gluconate, the anion of gluconic acid.

Occurrence

Gluconic acid is present in small amounts in honey and wine. Also Kombucha, a drink made ​​from fermented tea, and bionade contain gluconic acid.

Production and representation

D- gluconic acid can be obtained in the synthesis by chemical means by mild oxidation of D-glucose with bromine or iodine in alkaline solution. Enzyme- D- gluconic acid is formed by microbial oxidation of D- glucose with Aspergillus niger. The enzyme involved glucose oxidase is embedded in the cell wall.

Chemical Properties

In the acidic medium or in an attempt to isolate the free acid from solutions formed from D- gluconic very easy elimination of water D- gluconolactone ( glucono- δ - lactone). D- gluconic acid is therefore commercially only in the form of aqueous solutions or in the form of its salts obtainable.

Use

Food

Gluconic acid (E 574 ) and its salts are used in foods as an artificial acidity regulator, as a stabilizer or as calcium gluconate (E 578 ) and calcium lactate gluconate as a calcium source. Ferrous gluconate (E 579 ) is used for intense blackening of black olives. D- gluconolactone is used as a food additive E 575. In the commercially available soft drink " bionade " gluconic acid is included as a product of a fermentation process. Excessive consumption of gluconic acid or gluconsäurehaltigen products can have a laxative effect.

Technology

Gluconic acid is used as a mild acid in Metallbeizmitteln.

Medicine

Ferrous gluconate is included in some medicines for iron deficiency. Other Metallgluconate included in vaccine preparations, for example zinc gluconate. Gluconate is well absorbed ( absorbed ). This " drags " the anion than the bound cation with trace element in the body, allowing its efficient uptake. This effect can also be seen on the skin: After hydrofluoric acid burns a calcium gluconate gel is massaged into the skin. The gluconate facilitates the absorption of calcium, which makes harmless by formation of insoluble calcium fluoride in the body the toxic soluble fluoride.