Maltose

Structural formula
	Structural formula of α-maltose
General
Surname	Maltose
other names	Malt sugar; Barley sugar; Finetosis; Finetose F; Maltobiosis; Maltodiosis; Sunmalt; Sunmalt S.; 4- O - (α- D glucopyranosyl) - D -glucopyranose;
Molecular formula	C 12 H 22 O 11
Brief description	white, odorless, sweet-tasting, needle-shaped crystals
External identifiers / databases
EC number	200-716-5
ECHA InfoCard	100,000,651
PubChem	439186
ChemSpider	6019
DrugBank	DB03323
Wikidata	Q170002
properties
Molar mass	342.30 g mol −1
Physical state	firmly
Melting point	160–165 ° C (anhydrous); 102-103 ° C (monohydrate);
solubility	good in water (1080 g l −1 at 20 ° C); insoluble in organic solvents;
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
Toxicological data	> 44 g kg −1 ( LD 50 , mouse , oral ) ; 34.8 g kg −1 ( LD 50 , rat , oral ) ;
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Maltose or malt sugar is a breakdown product of starch . It is a white, crystalline double sugar (disaccharide) with the empirical formula C ₁₂ H ₂₂ O ₁₁ . It dissolves well in water and has a sweetish taste. Based on sucrose , a 10% D -maltose solution has a sweetening power of 41%. The monohydrate is formed when it crystallizes out from aqueous solutions . Maltose comes u. a. in barley sprouts and in potato sprouts.

Maltose should not be confused with maltulose .

Occurrence

Barley malt (= germinating barley)

Maltose is an ingredient in malt .

Maltose is produced during malting , i.e. the germination of grain, such as B. Barley . Maltose is found in beer , cereals, pasta , potatoes and in many other sweet-tasting products, in which it is formed when starch and glycogen are broken down with α-amylase . Maltose is formed u. a. when brewing beer through the action of amylases on starch in yields of ~ 80%.

Chemical properties

The chemical name for maltose is α - D -glucopyranosyl- (1 → 4) - D -glucopyranose, i.e. H. two D - glucose - molecules are linked to one another acetal-like via a glycosidic and an alcoholic OH group (condensation reaction) (1 → 4- α - glycosidic bond ).

Maltose is in equilibrium between cyclic and open form.

The (1 → 6) -linked compound, α - D -glucopyranosyl- (1 → 6) - D -glucopyranose, is known for short as isomaltose .

use

As an alternative to sucrose , maltose is used in various nutrient media in cell and tissue culture .

Detection reactions

Maltose can be detected semi-quantitatively in an aqueous solution at 70 ° C with ammonia solution ( Wöhlk reaction ) or methylammonium chloride solution ( Fearon 's test) through the formation of a red color.

safety instructions

Maltose is toxic in extremely high doses (LD ₅₀ > 44 g · kg ⁻¹ in the mouse, 34.8 g · kg ⁻¹ in the rat). Diarrhea occurs at lower doses .

Individual evidence

↑ ^a ^b ^c ^d ^e data sheet maltose (PDF) from Merck , accessed on January 19, 2011.
↑ Entry on maltose. In: Römpp Online . Georg Thieme Verlag, accessed on November 10, 2014.
^ ^A ^b J. Buckingham: Dictionary of Natural Products. CRC Press, 1994, ISBN 0-412-46620-1 , p. 3758.
↑ ^a ^b Entry on maltose in the ChemIDplus database of the United States National Library of Medicine (NLM) .
↑ ^a ^b Drugs in Japan. 1990, p. 1139.
↑ ^a ^b Yakuri to Chiryo. In: Pharmacology and Therapeutics. Vol. 7, 1979, p. 53.
^ Hans-Dieter Belitz, Werner Grosch, Peter Schieberle: Textbook of food chemistry. 6th, completely revised edition. Springer, Berlin 2008, ISBN 978-3-540-73201-3 , p. 263.
↑ Eckehard Buddecke: Outline of Biochemistry. 6th edition. Walter de Gruyter Verlag, 1980, ISBN 3-11-008388-4 , p. 165.
↑ SRL Fuentes, MBP Calheiros et al .: The effects of silver nitrate and different carbohydrate sources on somatic embryogenesis in Coffea canephora. In: Plant Cell Tissue and Organ Culture. 60 (1) 2000, pp. 5-13.
↑ M. Nageli, JE Schmid et al .: Improved formation of regenerable callus in isolated microspore culture of maize: impact of carbohydrates, plating density and time of transfer. In: Plant Cell Reports. 19 (2) 1999, pp. 177-184.
↑ Klaus Ruppersberg: Starch digestion by saliva - what does that actually result? A simple maltose detection at the end of the enzymatic hydrolysis of amylose and the surprising presence of glucose in a ratio of 1:15 . In: MNU Journal . tape 69 , no. 5 , 2016, ISSN 0025-5866 ( pedocs.de [accessed on May 3, 2018]).

Web links

Commons : Maltose - collection of images, videos and audio files

[Merck-1] ↑ ^a ^b ^c ^d ^e data sheet maltose (PDF) from Merck , accessed on January 19, 2011.

[2] Entry on maltose. In: Römpp Online . Georg Thieme Verlag, accessed on November 10, 2014.

[Buckingham-3] A ^b J. Buckingham: Dictionary of Natural Products. CRC Press, 1994, ISBN 0-412-46620-1 , p. 3758.

[chemid-4] Entry on maltose in the ChemIDplus database of the United States National Library of Medicine (NLM) .

[dij-5] Drugs in Japan. 1990, p. 1139.

[yakuri-6] Yakuri to Chiryo. In: Pharmacology and Therapeutics. Vol. 7, 1979, p. 53.

[7] Hans-Dieter Belitz, Werner Grosch, Peter Schieberle: Textbook of food chemistry. 6th, completely revised edition. Springer, Berlin 2008, ISBN 978-3-540-73201-3 , p. 263.

[Buddecke-8] Eckehard Buddecke: Outline of Biochemistry. 6th edition. Walter de Gruyter Verlag, 1980, ISBN 3-11-008388-4 , p. 165.

[9] SRL Fuentes, MBP Calheiros et al .: The effects of silver nitrate and different carbohydrate sources on somatic embryogenesis in Coffea canephora. In: Plant Cell Tissue and Organ Culture. 60 (1) 2000, pp. 5-13.

[10] M. Nageli, JE Schmid et al .: Improved formation of regenerable callus in isolated microspore culture of maize: impact of carbohydrates, plating density and time of transfer. In: Plant Cell Reports. 19 (2) 1999, pp. 177-184.

[11] Klaus Ruppersberg: Starch digestion by saliva - what does that actually result? A simple maltose detection at the end of the enzymatic hydrolysis of amylose and the surprising presence of glucose in a ratio of 1:15 . In: MNU Journal . tape 69 , no. 5 , 2016, ISSN 0025-5866 ( pedocs.de [accessed on May 3, 2018]).