Maltose

Maltose
IUPAC name 2-(hydroxymethyl)-6-[4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyox ane-3,4,5-triol
Other names 4-O-α-D-Glucopyranosyl-D-glucose Isomaltose 6-O-α-D-Glucopyranosyl-D-glucose
Identifiers
CAS number	69-79-4 Y
PubChem	6255, 439193 (isomaltose)
ChemSpider	388329 α-maltose Y, 6019 β-maltose
UNII	66Y63L379N Y
EC-number	200-716-5
ChEBI	CHEBI:17306 N
ChEMBL	CHEMBL1234209 N
Jmol-3D images	Image 1
SMILES O([C@H]1[C@H](O)[C@@H](O)C(O)O[C@@H]1CO)[C@H]2O[C@@H]([C@@H](O)[C@H](O)[C@H]2O)CO
InChI InChI=1S/C12H22O11/c13-1-3-5(15)6(16)9(19)12(22-3)23-10-4(2-14)21-11(20)8(18)7(10)17/h3-20H,1-2H2/t3-,4-,5-,6+,7-,8-,9-,10-,11?,12-/m1/s1 Y Key: GUBGYTABKSRVRQ-PICCSMPSSA-N Y InChI=1S/C12H22O11/c13-1-3-5(15)6(16)9(19)12(22-3)23-10-4(2-14)21-11(20)8(18)7(10)17/h3-20H,1-2H2/t3-,4-,5-,6+,7-,8-,9-,10-,11?,12-/m1/s1
Properties[1]
Molecular formula	C12H22O11
Molar mass	342.30 g/mol
Appearance	white powder or crystals
Density	1.54 g/cm3
Melting point	160–165 °C (anhydrous) 102-103 °C (monohydrate)
Solubility in water	1.080 g/mL (20 °C)
Chiral rotation [α]D	+140.7º (H2O, c = 10)
Hazards
MSDS	External MSDS
EU Index	not listed
Related compounds
Related	Sucrose Lactose Trehalose Cellobiose
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Maltose (pronounced /ˈmɒltoʊz/), or malt sugar, is a disaccharide formed from two units of glucose joined with an α(1→4)bond, formed from a condensation reaction. The isomer "isomaltose" has two glucose molecules linked through an α(1→6) bond. Maltose is the second member of an important biochemical series of glucose chains. Maltose is the disaccharide produced when amylase breaks down starch. It is found in germinating seeds such as barley as they break down their starch stores to use for food. It is also produced when glucose is caramelized. ^[2]

The addition of another glucose unit yields maltotriose; further additions will produce dextrins (also called maltodextrins) and eventually starch (glucose polymer).^{[citation needed]}

Maltose can be broken down into two glucose molecules by hydrolysis. In living organisms, the enzyme maltase can achieve this very rapidly. In the laboratory, heating with a strong acid for several minutes will produce the same result. Isomaltose is broken by isomaltase.^{[citation needed]}

The production of maltose from germinating cereals, such as barley, is an important part of the brewing process. When barley is malted, it is brought into a condition in which the concentration of maltose-producing amylases has been maximized. Mashing is the process by which these amylases convert the cereal's starches into maltose. Metabolism of maltose by yeast during fermentation then leads to the production of ethanol and carbon dioxide.^{[citation needed]}

The structure of β-maltose

Maltose as food

Plain maltose has a sweet taste, about half as sweet as glucose and about one-sixth as sweet as fructose.^{[citation needed]}

Maltose syrup

In Southern China, Taiwan, Hong Kong and Macau, maltose is a common ingredient in confectionery. The most common way to consume it is to put a layer of maltose between two pieces of biscuit (usually crackers).^{[citation needed]}

Maltose with biscuits

External links

• Detailed Views of Maltose Binding Protein
• Elmhurst College Virtual Chembook

References

1. ^ Weast, Robert C., ed (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, FL: CRC Press. p. C-367. ISBN 0-8493-0462-8. .
2. ^ Journal of Food Science, July 1966.