Key difference - maltose vs. sucrose

Carbohydrates, which are an essential macromolecule for all living things in the world, can be divided into three categories known as monosaccharides, disaccharides, and polysaccharides. Maltose and sucrose are considered to be the simplest and most abundant disaccharides in the world. However, there seems to be a lot of confusion about the difference between maltose and sucrose as they have a similar formula (C ₁₂ H ₂₂ O ₁₁₎ and molecular weight (342.30 g / mol). Both maltose and sucrose are made when two simple sugars combine. The main difference between maltose and sucrose is that maltose is a combination of two glucose molecules, while sucrose is a combination of glucose and fructose . In addition, maltose is a reducing sugar while sucrose is a non-reducing sugar.

This article describes

1. What is maltose? - Definition, structure, synthesis and properties

2. What is sucrose? - Definition, structure, synthesis and properties

3. What is the difference between maltose and sucrose?

What is maltose?

Maltose is a disaccharide sugar and its monomer unit is glucose. It is also called maltobiose or malt sugar . To synthesize a maltose molecule, two glucose molecules are linked by a condensation reaction with an α (1 → 4) glycosidic bond. Starch is broken down into maltose in the presence of the amylase enzyme. Maltose is produced during seed germination and glucose caramelization.

Maltose syrup

What is sucrose

Sucrose is a non-reducing sugar and is also known as sucrose because it is mainly found in many plants. Its molecular formula is C ₁₂ H ₂₂ O ₁₁ . It can be isolated from cane or beet sugar and used for human consumption. Sucrose is particularly important for the beverage industry and baked goods, as it helps improve taste and palatability as well as color development. However, excessive consumption of sucrose is directly related to health conditions such as tooth decay, glycemic index, and rapid spikes in blood sugar levels that lead to diabetes mellitus and obesity.

Granulated sugar

Difference between maltose and sucrose

story

Maltose was first introduced in 1872 by the Irish chemist and brewer Cornelius O'Sullivan.

Sucrose was first described by the English chemist William Miller in 1857.

Natural sources

Maltose occurs naturally in beer, grains such as barley and wheat , pasta, soybeans, potatoes, and sweet potatoes .

Sucrose is stored in plants because it is less reactive. It is naturally found in cane or beet sugar and is used to make table sugar . In 2013 the average sucrose production worldwide was 175 million tons.

Alternative names

Maltose is also known as 4-O-α-D-glucopyranosyl-D-glucose, maltobiose, and malt sugar.

Sucrose is also known as sugar, sucrose, α-D-glucopyranosyl- (1 → 2) -β-D-fructofuranoside, dodecacarbon monodecahydrate, β-D-fructofuranosyl- (2 → 1) -α-D-glucopyranoside, β- (2S, 3S, 4S, 5R) -Fructofuranosyl-α- (1R, 2R, 3S, 4S, 5R) -glucopyranoside, α- (1R, 2R, 3S, 4S, 5R) -glucopyranosyl-β- (2S, 3S , 4S, 5R) fructofuranoside

Monomer units

Maltose is a disaccharide that is formed from two glucose units.

Sucrose is a disaccharide that is formed from glucose units and fructose units.

IUPAC name

The IUPAC name of maltose is 2- (hydroxymethyl) -6- [4,5,6-trihydroxy-2- (hydroxymethyl) oxan-3-yl] oxyox ane-3,4,5-triol.

The IUPAC name of sucrose is (2R, 3R, 4S, 5S, 6R) -2 - [(2S, 3S, 4S, 5R) -3,4-dihydroxy-2,5-bis (hydroxymethyl) oxolane-2- yl] oxy-6- (hydroxymethyl) oxane-3,4,5-triol.

Molecular structure

Sucrose is a disaccharide combination of the monosaccharides glucose and fructose, linked with an α (1 → 4) bond, which is formed by a condensation reaction. Its chemical formula is C12H22O11. On the other hand, hydrolysis breaks the glycosidic bond, converting sucrose into glucose and fructose.

Molecular formula of sucrose

Maltose is a disaccharide combination of the two molecules of the monosaccharide glucose, which are linked with an α (1 → 4) bond and are formed by a condensation reaction. Its chemical formula is C12H22O11. On the other hand, hydrolysis breaks the glycosidic bond, converting maltose into glucose.

Molecular formula of maltose

Chiral rotation

The purity of maltose can be measured by polarimetry. The rotation of plane polarized light through a maltose solution is + 140.7 °.

The purity of sucrose can be measured by polarimetry. The rotation of plane polarized light through a sucrose solution is + 66.47 °.

Biochemical synthesis process

Maltose is synthesized in

• Seed germination process
• Caramelization reaction
• Starch degradation due to the action of amylase during oral digestion and pancreatic digestion

Sucrose is synthesized in beet sugar and in cane during photosynthesis.

Reducing properties

Maltose is a reducing sugar and has a free aldehyde group. Thus it can reduce Fehling's reagent.

Sucrose is a non-reducing sugar because it has no anomeric hydroxyl groups. Thus it cannot reduce Fehling's reagent.

Osazon crystal formation

Maltose forms petal-shaped crystals. The Osazon test can be used to identify maltose from other sugars.

Sucrose is a non-reducing sugar and does not form Osazon crystals.

In summary, maltose and sucrose are primarily sugars and chemically they are categorized as disaccharides that are used as sweeteners. Compared to maltose, sucrose is a highly available food ingredient. However, the safety of long-term consumption of these natural sugars is debatable.

References:

West, Robert C., eds. (1981). CRC Handbook of Chemistry and Physics ^(62nd ed.). Boca Raton, FL: CRC Press. P. C-367.

Lombardo, YB, Drago, S., Chicco, A., Fainstein-Day, P., Gutman, R., Gagliardino, JJ, Gomez Dumm, CL (1996). Long-term administration of a sucrose-rich diet to normal rats: relationship between metabolic and hormonal profiles and morphological changes in the endocrine pancreas. Metabolism. 45 (12): 1527-32.

Mintz, Sydney (1986). Sweetness and Power: The Place of Sugar in Modern History. Penguin. ISBN 978-0-14-009233-2.

Image courtesy:

“Saccharose2” by NEUROtiker - Own work (Public Domain) via Commons Wikimedia

“Maltose2” by NEUROtiker - Own work (Public Domain) via Commons Wikimedia

“Sugar 2xmacro” by Lauri Andler (Phantom) - Own work (CC BY-SA 3.0) via Commons Wikimedia

“Maltose syrup” From www.aziatische-ingredienten.nl (CC BY-SA 2.0) via Commons Wikimedia