Sorbitol

• D-(- ) sorbitol, D- (-) sorbitol
• D-(- ) -glucitol, D- (-)- glucitol
• IUPAC: (2R, 3R, 4R, 5S) -hexane -1 ,2,3,4,5,6 - hexol
• Hexanhexol
• E 420
• Sorbitolum

• A06AD18
• A06AG07
• B05CX02
• V04CC01

Colorless, odorless, hygroscopic needles with a sweet taste

Fixed

1.49 g · cm -3 ( 20 ° C)

110-112 ° C ( anhydrous)

295 ° C (4.7 hPa)

13.57

Very slightly soluble in water: 2750 g · l-1 (30 ° C)

15.9 g · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Sorbitol [ zɔrbi ː t ] (the sorbitol, and sorbitol, glucitol or Hexanhexol ) is one of the alditols (sugar alcohols ) and is used in many foods industrially produced ( food additive E420) as a sugar substitute, carrier and humectant use. Sorbitol is the reduced Polyolform the hexoses, glucose, fructose, and sorbose and can be produced from them by catalytic or electrochemical hydrogenation.

Occurrence and production

Originally sorbitol from the fruits of mountain ash ( rowan, Sorbus aucuparia ) has been obtained, which contain up to 12 % sorbitol. He is also found in many other fruits and particularly in the core of fruit. Worth mentioning are pears, plums, apples, apricots and peaches in terms of their high content of sorbitol. In contrast, berries and citrus fruits and pineapple and grapes contain very little to no sorbitol.

Industrial Prepared from corn and wheat starch. Sorbitol is obtained on the basis of glucose (grape sugar). As with all products that are produced on the saccharification of starch in Europe, with sorbitol are not genetically engineered products on the market, but for the production of sorbitol, the use of genetically modified organisms would be possible.

Use and characteristics

Sorbitol provides 2.4 kcal / g (10 kJ / g ) less calories than table sugar (sucrose ) (17 kJ / g). Its sweetening power equivalent to about 40-60 % in comparison to sucrose. For the metabolism in the body no insulin is needed. Therefore, sorbitol is suitable to sweeten diabetic foods and comes in Germany and Austria in these dietary foods for use.

In the food production of sorbitol is also used as a humectant because it has hygroscopic properties and thus food ( for example, mustard, mayonnaise, toast, biscuit, chocolate and praline fillings), cosmetics and even toothpaste protects against drying out.

Since sorbitol is reduced only slightly in the mouth, it is only slightly cariogenic. Sorbitol is part of most toothpastes, which can be found on the market. It is approved in the EU as a food additive under the E number 420, with the exception of drinks as an additive for almost all foods in arbitrarily high amount, although recorded amounts greater than 50 g / day to diarrhea, bloating and abdominal pain may result. Any food that contains more than 10% sorbitol or other polyols, must therefore also the wording: " ... may have a laxative effect if consumed to excess. " Wear.

In the esterification of sorbitol with nitrating acid is produced nitro orbit, one industrial explosives, similar to nitroglycerin.

Sorbitol further serves as an intermediate in the synthesis of ascorbic acid ( vitamin C) from D-glucose (dextrose ) to Reichstein, for which it is oxidized to the corresponding ketose, L- sorbose, the next intermediate product.

Intolerance

In a Sorbitunverträglichkeit ( = Sorbitmalabsorption, Sorbitintoleranz ) the recovery of sorbitol is released in the small intestine in whole or in part. Is a Sorbitunverträglichkeit diagnosed, you should avoid products that contain sorbitol as sugar substitute. Particular caution is advised in diabetic foods and Diät-/Lightprodukten. Also, make sure that in almost all conventional chewing gums and lozenges sorbitol is included. Also found in many local varieties of fruit, such as peach ( 0.9 g/100 g), apricot (0.82 g/100 g) or plum (1.4 g/100 g ) a non- negligible quantity of sorbitol. In the dried fruit, the concentration is even higher due to the loss of water; so is the concentration in dried apricots good about five times as high (4.6 g/100 g) as in fresh fruit.

People with fructose intolerance may also take no sorbitol to, since it is converted to fructose in the metabolism.

In these patients, Sorbitintoleranz, in addition to fructose are present, but this requires a separate medical investigation.

Biochemistry

Sorbitol in the intermediate stage of the organism is outside the liver Polyolweges occurring and can be converted to both glucose and fructose to. In addition to the reduction of through diet fed sorbitol This path is to synthesize glucose from fructose, especially in the vesicle fluid to nourish the sperm. The enzyme aldose reductase converts glucose to under consumption of NADPH / H in sorbitol, the enzyme sorbitol dehydrogenase oxidizes sorbitol to fructose, this time winning a NADH / H .

The metabolism of sorbitol plays a role in the emergence of some late complications of diabetes mellitus. In non-physiological high glucose range of Polyolweg is taken, the equilibrium lies on the side of sorbitol and fructose. Since fructose is virtually eliminated only in the liver and sorbitol and fructose, the cells can not leave it and move accumulate the osmotic balance of the cell, which ultimately leads to cell swelling. In particular, the formation of cataracts is attributed to this mechanism, but it also plays a role in diabetic microangiopathy and neuropathy.

Therapeutic Application

In high doses, sorbitol acts through its water attraction as an osmotic diuretic. The same mechanism of action due to its possible use as an enema.