What Happens to Sucrose During Hydrolysis?

December 2, 2025 •

3 min read

Over 160 million metric tons of sucrose are produced globally every year, but what happens to sucrose during hydrolysis is critical for its use in food, industry, and biological processes. This process breaks the disaccharide down into its sweeter, more versatile components: glucose and fructose.

Quick Summary

Sucrose undergoes hydrolysis, a chemical reaction involving water, to cleave its glycosidic bond, resulting in an equimolar mixture of the monosaccharides glucose and fructose. This reaction can be catalyzed by an enzyme like invertase or by an acid, and is an essential process in digestion and food manufacturing.

Key Points

Breakdown into Monosaccharides: During hydrolysis, the disaccharide sucrose is split into two simpler sugar units, the monosaccharides glucose and fructose.
Water is the Reactant: The reaction requires a molecule of water to break the glycosidic bond that links the glucose and fructose units in sucrose.
Reaction Catalysts: Hydrolysis of sucrose can be accelerated by either an enzyme, such as invertase (found in nature and used in industry), or by an acid.
Creates Invert Sugar: The resulting 1:1 mixture of glucose and fructose is called invert sugar, valued for its higher sweetness and resistance to crystallization compared to sucrose.
Changes Optical Rotation: The reaction inverts the optical rotation of polarized light from a positive (dextrorotatory) value to a negative (levorotatory) one.
Essential for Digestion: In human digestion, the enzyme sucrase in the small intestine hydrolyzes sucrose to allow for the absorption of glucose and fructose into the bloodstream.
Important Industrial Process: Industrially, sucrose hydrolysis is used in the production of food items like syrups, candies, and jams, as well as in biotechnology.

Understanding the Basics of Sucrose and Hydrolysis

Sucrose, commonly known as table sugar, is a disaccharide formed from two simpler sugar units, glucose and fructose, linked by a glycosidic bond. This linkage involves the anomeric carbons of both monosaccharides, making sucrose a non-reducing sugar. Hydrolysis is a chemical process where water is used to break a chemical bond, and in the case of carbohydrates, it's known as saccharification.

The Chemical Equation for Sucrose Hydrolysis

During hydrolysis, a water molecule reacts with sucrose, breaking the glycosidic bond and yielding one molecule of glucose and one molecule of fructose. The reaction is represented as: $C{12}H{22}O_{11} (sucrose) + H_2O (water) \to C6H{12}O_6 (glucose) + C6H{12}O_6 (fructose)$

Inversion: The Change in Optical Rotation

A key characteristic of sucrose hydrolysis is the change in optical rotation, leading to the term 'invert sugar'. Sucrose rotates plane-polarized light to the right (dextrorotatory, +66.47°). The resulting mixture of glucose (mild dextrorotatory) and fructose (stronger levorotatory) rotates light to the left, as fructose's rotation is more significant. This shift from right to left is the 'inversion'.

Catalysts for Sucrose Hydrolysis

Sucrose hydrolysis requires a catalyst. Two main methods exist:

Enzymatic Hydrolysis with Invertase

Invertase (sucrase) is a common enzyme used in the food industry for this process. It specifically binds to sucrose, facilitates the addition of water to the glycosidic bond, and releases glucose and fructose.

Acidic Hydrolysis

Dilute mineral acids, like hydrochloric acid, can also catalyze the reaction. The acid weakens the glycosidic bond, and water then splits the molecule. Higher temperatures increase the reaction rate in acidic hydrolysis.

Comparison of Catalysis Methods for Sucrose Hydrolysis


Feature	Enzymatic Hydrolysis (Invertase)	Acidic Hydrolysis (Mineral Acid)
Catalyst	β-fructofuranosidase (Invertase)	Dilute mineral acid (e.g., HCl)
Operating Conditions	Mild conditions, typically optimal pH 4.5 and around 60°C.	Elevated temperatures (e.g., 65-85°C) and low pH are required.
Product Purity	Higher purity with fewer side products.	Can produce unwanted byproducts and off-flavors, especially at higher temperatures.
Catalyst Cost	More expensive initially due to the cost of the enzyme.	Very low cost, as mineral acids are cheap and readily available.
Process Control	Highly specific and controllable reaction rates.	Less precise control, with reaction rate sensitive to temperature and acid concentration.
Industrial Use	Preferred for food-grade products where purity and taste are crucial.	Used in industrial processes where cost is a major factor and slight impurity is acceptable.

The Role of Sucrose Hydrolysis in Living Organisms

Sucrose hydrolysis is vital in plants and animals. In human digestion, sucrase in the small intestine breaks down dietary sucrose into glucose and fructose for absorption. In plants, sucrose is transported and then hydrolyzed for energy use.

Industrial Applications of Sucrose Hydrolysis

The food industry extensively uses sucrose hydrolysis to produce invert sugar. Invert sugar is sweeter than sucrose, more soluble, and resists crystallization, making it useful in candies, syrups, and jams. It is also a key component of honey. Hydrolyzed sucrose is also used in biotechnology for fermentation processes. For more on industrial applications, refer to research like that available on ScienceDirect.

Conclusion

Sucrose hydrolysis is the breakdown of sucrose into glucose and fructose through reaction with water. This process, catalyzed by enzymes like invertase or by acids, is crucial for biological functions such as digestion and has significant industrial applications, particularly in creating invert sugar. Understanding what happens to sucrose during hydrolysis highlights its importance in both natural systems and manufactured goods.

Frequently Asked Questions

The chemical equation for the hydrolysis of sucrose is $C{12}H{22}O_{11} + H_2O \to C6H{12}O_6 + C6H{12}O_6$. One sucrose molecule plus one water molecule yields one glucose molecule and one fructose molecule.

Invert sugar is the equimolar mixture of glucose and fructose that results from the hydrolysis of sucrose. It gets its name from the inversion of optical rotation that occurs during the reaction.

The enzyme that catalyzes the hydrolysis of sucrose is called invertase (or sucrase). In human digestion, the enzyme sucrase serves this function.

Hydrolyzing sucrose to create invert sugar is important in the food industry because invert sugar is sweeter, more soluble, and less prone to crystallization than sucrose. This makes it ideal for use in candies, syrups, and confections.

Enzymatic hydrolysis uses the enzyme invertase and occurs under milder, more controlled conditions to produce high-purity invert sugar. Acidic hydrolysis uses a mineral acid and higher temperatures, is cheaper, but can create more side products and off-flavors.

During human digestion, the enzyme sucrase on the intestinal wall breaks down sucrose into glucose and fructose, which are then absorbed into the bloodstream for energy.

Yes, hydrolysis increases the sweetness. Sucrose is hydrolyzed into glucose and fructose, and since fructose is significantly sweeter than glucose, the resulting invert sugar mixture is sweeter than the original sucrose.

Honeybees use the enzyme invertase to hydrolyze the sucrose from nectar. This creates the mixture of glucose and fructose that is the main ingredient of honey.