How to Convert Sugar into Glucose: A Guide to Hydrolysis

December 13, 2025 •

3 min read

Did you know that table sugar, or sucrose, is a disaccharide made of equal parts glucose and fructose? This guide explains how to convert sugar into glucose by breaking down the sucrose molecule through a process called hydrolysis.

Quick Summary

Sucrose is converted into glucose and fructose via hydrolysis, either using enzymes like invertase or through an acid-catalyzed reaction, a process used in food science.

Key Points

Hydrolysis: Converting sucrose (table sugar) into glucose and fructose requires hydrolysis, a chemical reaction that breaks the sugar molecule with water.
Enzymatic Method: The enzyme invertase is a highly efficient biological catalyst for converting sucrose into glucose and fructose, used in both digestion and food manufacturing.
Acidic Method: The conversion can be accelerated by using a mild acid, like lemon juice or cream of tartar, combined with heat to create invert sugar.
Natural Digestion: Our bodies naturally convert sucrose into glucose and fructose in the small intestine using the enzyme sucrase before absorption.
Invert Sugar: The resulting mixture of glucose and fructose, known as invert sugar, has functional benefits in cooking, such as retaining moisture and preventing crystallization.
Glucose vs. Sucrose: Sucrose is a disaccharide, while glucose is a monosaccharide. Glucose is the simple sugar form our bodies use directly for energy.

The Science of Sugar Conversion: Understanding Hydrolysis

Table sugar, known as sucrose ($C{12}H{22}O_{11}$), is a disaccharide composed of one glucose molecule ($C6H{12}O_6$) and one fructose molecule ($C6H{12}O6$) linked together. The process to convert sugar into glucose involves breaking this link through hydrolysis. This chemical reaction uses a water molecule to split the bond, yielding an equimolar mixture of glucose and fructose, commonly called invert sugar. The reaction is represented as: $C{12}H{22}O{11} + H_2O \to C6H{12}O_6 \text{(glucose)} + C6H{12}O_6 \text{(fructose)}$. While this reaction can happen slowly on its own, catalysts are typically used to speed it up. There are two main catalytic methods: using enzymes or using a dilute acid, often with heat.

Method 1: Enzymatic Hydrolysis

Using the enzyme invertase (sucrase) is a specific and gentle way to hydrolyze sucrose. This method is naturally employed in human digestion and by bees in honey production. Enzymes, as biological catalysts, bind to sucrose and facilitate the breaking of the glycosidic bond with water, releasing glucose and fructose. Enzymatic hydrolysis is common in commercial food production to make invert sugar for its moisture retention and anti-crystallization properties.

Method 2: Acid-Catalyzed Hydrolysis

Acids can also catalyze the hydrolysis of sucrose, especially when heated. This process is used to create invert sugar syrup. A simple home method uses ingredients like lemon juice or cream of tartar as the acid.

How to Create Invert Sugar at Home

By heating a solution of sugar and water with a small amount of acid, the hydrolysis reaction is accelerated. The mixture is simmered until it reaches a specific temperature, resulting in a syrup that thickens upon cooling. This homemade invert sugar, a glucose and fructose mixture, is beneficial in baking to prevent crystallization.

Ingredients:

Granulated sugar (sucrose)
Water
Lemon juice or cream of tartar

Instructions:

Dissolve sugar in water over low heat.
Add acid (e.g., 1 tbsp lemon juice per 4 cups sugar) and simmer.
Cook without stirring, brushing down side crystals.
Heat until the soft-ball stage (around 235°F / 113°C).
Let cool to thicken.

Comparison of Conversion Methods


Feature	Enzymatic Hydrolysis	Acid-Catalyzed Hydrolysis
Catalyst	Enzyme (e.g., invertase)	Acid (e.g., citric acid, HCl)
Conditions	Mild temperature and pH	Heat required for rapid reaction
Selectivity	Highly specific for sucrose	Less specific; can lead to side products
Products	Equimolar mixture of glucose and fructose	Equimolar mixture of glucose and fructose, with potential for side products
Reaction Speed	Fast and efficient	Slower than enzymatic, relies on temperature
Common Use	Industrial food production, biological digestion	Industrial and home invert sugar production

The Body's Conversion Process

Our bodies convert dietary carbohydrates into glucose for energy. Sucrose is broken down in the small intestine into glucose and fructose by sucrase. These are absorbed, with glucose used directly for energy and fructose processed by the liver. This natural enzymatic process is the body's way of converting sucrose to its simpler sugars. For a deeper look into the intricate world of carbohydrate chemistry, a valuable resource is provided by Chemistry LibreTexts, which explains the hydrolysis of sucrose.

Conclusion: Breaking Bonds for Sweeter Results

Converting sugar (sucrose) into glucose is achieved through hydrolysis, breaking the disaccharide into glucose and fructose. This can be done enzymatically with invertase for purity or with acid and heat for simpler applications. This process is crucial in food science, baking, and biological digestion, demonstrating how complex sugars become simpler ones for various uses, including energy.

Frequently Asked Questions

No, a simple home method of hydrolysis will produce an equimolar mixture of glucose and fructose, known as invert sugar, not pure glucose. Isolating pure glucose from this mixture is a more complex chemical process.

Table sugar is sucrose, a disaccharide composed of one glucose molecule and one fructose molecule linked together. Glucose is a simple, single-unit sugar.

The acid in the lemon juice or cream of tartar acts as a catalyst for the hydrolysis reaction, speeding up the process of breaking down sucrose into glucose and fructose when heated.

Yes, when you eat foods containing sucrose, your body uses the enzyme sucrase in the small intestine to break it down into glucose and fructose for absorption into the bloodstream.

Invert sugar is valued for its ability to prevent crystallization and improve moisture retention in confections and baked goods, leading to a smoother texture and longer shelf life.

Yes, our bodies have a metabolic pathway in the liver that converts fructose into glucose for energy. Industrially, the enzyme glucose isomerase can be used.

Other more complex carbohydrates, like starches (polysaccharides) and lactose (a disaccharide), can also be broken down into glucose through hydrolysis using specific enzymes.