What Does Maltose Split Into? The Complete Breakdown

January 11, 2026 •

4 min read

Maltose, often called malt sugar, is a disaccharide composed of two linked glucose units. To convert this sugar into a usable energy source, the body must break it down into its simpler components. So, what does maltose split into? It is split into two simple glucose molecules through a chemical process known as hydrolysis.

Quick Summary

Maltose is broken down into two individual glucose molecules via a hydrolysis reaction primarily facilitated by the enzyme maltase, a key part of carbohydrate digestion in the small intestine.

Key Points

Maltose Splits into Glucose: The disaccharide maltose breaks down exclusively into two molecules of the monosaccharide glucose through a process called hydrolysis.
Maltase Enzyme Is Required: The splitting of maltose is catalyzed by the enzyme maltase, which is found in the brush border of the small intestine.
Hydrolysis Is The Reaction: The chemical process that breaks the alpha-1,4 glycosidic bond linking the two glucose units is called hydrolysis, which involves the addition of a water molecule.
Primary Energy Source: The resulting glucose molecules are absorbed into the bloodstream to serve as the body's main and most readily available energy source.
Intermediate Product of Starch Digestion: Maltose is often created as an intermediate sugar when larger carbohydrates, like starch, are digested by amylase in the mouth and small intestine.
Key to Fermentation: In industrial processes like brewing, maltose derived from starch provides the fermentable sugars that yeast use to produce alcohol and CO2.

The Chemical Hydrolysis of Maltose

Hydrolysis is the chemical reaction that uses water to break down a compound. For maltose, this process involves the splitting of its glycosidic bond. Maltose, with the chemical formula C${12}$H${22}$O${11}$, is a disaccharide formed from two alpha-D-glucose monosaccharides connected by an alpha-1,4 glycosidic linkage. The hydrolysis of maltose breaks this bond, adding a water molecule (H${2}$O) to yield two molecules of glucose (C${6}$H${12}$O$_{6}$).

The Key Enzyme: Maltase

In living organisms, this hydrolysis reaction doesn't happen spontaneously at a meaningful rate. It requires a specific biological catalyst, an enzyme known as maltase. Maltase is an alpha-glucosidase enzyme found in plants, bacteria, yeast, and the intestinal tract of vertebrates, including humans. The enzyme's active site is specifically shaped to bind with the maltose molecule, which it then cleaves into two glucose units. Without this enzyme, the digestion of maltose would be inefficient, leading to malabsorption issues.

The Chemical Reaction Formula

The hydrolysis of maltose can be represented by a straightforward chemical equation:

C${12}$H${22}$O${11}$ (Maltose) + H${2}$O (Water) → 2 C${6}$H${12}$O$_{6}$ (Glucose)

This reaction is the final step in breaking down maltose so the body can absorb its component sugars.

Where This Splitting Occurs in the Human Body

The digestion of carbohydrates is a multi-step process that begins in the mouth and is completed in the small intestine. The process involving maltose specifically unfolds in the following stages:

Mouth: Digestion starts with salivary amylase, which breaks down large starch molecules into smaller polysaccharides and maltose.
Stomach: The acidic environment of the stomach inactivates salivary amylase, so carbohydrate digestion largely pauses here.
Small Intestine: The bulk of carbohydrate digestion, including the splitting of maltose, occurs here. Pancreatic amylase is secreted into the small intestine to further break down any remaining starch into maltose and other sugars. The crucial final step takes place on the intestinal wall, where the enzyme maltase, located on the brush border, breaks the maltose into two glucose molecules.

After maltose has been fully digested, the resulting monosaccharides (glucose) are absorbed through the intestinal wall into the bloodstream. From there, the glucose is transported to cells throughout the body to be used for energy.

Why The Breakdown of Maltose Is Important

For the human body, the splitting of maltose is a critical step for several reasons:

Energy Production: Glucose is the body's primary and most readily usable source of energy. It is utilized through cellular respiration to produce adenosine triphosphate (ATP), the main energy currency of the cell. The breakdown of maltose ensures a steady supply of this vital fuel.
Nutrient Absorption: The two-unit maltose molecule is too large to be absorbed through the intestinal wall into the bloodstream directly. It must be split into its single-unit glucose components to pass through the intestinal epithelium.
Regulation of Blood Sugar: The efficient digestion and absorption of glucose from maltose help maintain stable blood sugar levels. Proper enzymatic function prevents undigested sugars from causing fermentation in the large intestine, which can lead to discomfort.

Maltose vs. Other Common Disaccharides

To understand maltose fully, it is useful to compare it with other well-known disaccharides like sucrose and lactose. While all three are double sugars, their chemical composition and the enzymes required for their digestion are distinct.


Feature	Maltose	Sucrose	Lactose
Composition	Two glucose molecules	One glucose and one fructose molecule	One glucose and one galactose molecule
Hydrolyzing Enzyme	Maltase	Sucrase	Lactase
Primary Sources	Malted grains (barley, wheat), starches, corn syrup	Sugar cane, sugar beets, fruits	Milk and dairy products
Taste	Mildly sweet, about 30–60% as sweet as sucrose	Very sweet (table sugar)	Mildly sweet
Digestion Location	Small intestine	Small intestine	Small intestine

Natural and Industrial Sources of Maltose

Maltose is not as abundant in its free form in nature as glucose or fructose but is a key intermediate product from the breakdown of starch. It is naturally found in sprouting grains like barley, which is why it is often called "malt sugar". Sweet potatoes, peaches, and pears also contain natural maltose. Industrially, it is produced in high quantities for use in food manufacturing.

Foods with Natural Maltose: Some breakfast cereals, baked goods, and syrups are derived from malted grains and can be a source of maltose. Cooked sweet potatoes are notably high in maltose, which accounts for their increased sweetness.
The Brewing Process: Maltose is a primary fermentable sugar in brewing beer. During the mashing process, enzymes in the malted barley break down starch into maltose, which yeast later consumes to produce alcohol and carbon dioxide.

Conclusion

In summary, maltose is fundamentally split into two molecules of glucose. This breakdown is a crucial biological process, essential for converting ingested carbohydrates into the primary energy source the body needs to function. It is catalyzed by the enzyme maltase, working primarily within the small intestine. By understanding what maltose splits into, we gain a clearer picture of how our bodies process and utilize carbohydrates for energy, from the digestion of a simple starch to the fermentation process in brewing. For more information on the maltase enzyme and its function, see the detailed overview on Britannica.com.

Frequently Asked Questions

The chemical equation for the hydrolysis of maltose is C${12}$H${22}$O${11}$ (maltose) + H${2}$O (water) → 2 C${6}$H${12}$O$_{6}$ (glucose).

The splitting of maltose is completed in the small intestine. Specifically, the enzyme maltase is located on the microvilli of the intestinal wall, where it breaks down the maltose molecule.

After maltose is split into glucose, the glucose molecules are absorbed through the wall of the small intestine into the bloodstream. From there, they are transported to cells for energy production or stored as glycogen in the liver and muscles.

Maltose is a disaccharide, which is a type of simple carbohydrate or simple sugar. It is made from two simpler sugar units (monosaccharides) joined together.

In the human digestive system, maltose is primarily produced by the action of amylase enzymes on starch. Amylase breaks down the long polysaccharide chains of starch into smaller units, including maltose.

Maltose is found in malted grains like barley and wheat, as well as products made from them, including certain breads, cereals, and beer. It is also present in foods like sweet potatoes, peaches, and corn syrup.

A deficiency in maltase can lead to maltose intolerance. This means the body cannot effectively break down and absorb maltose, leading to gastrointestinal symptoms such as bloating, cramps, and diarrhea as the undigested sugar ferments in the large intestine.