Sucrose is the common chemical name for table sugar. Sucrose is a disaccharide; each molecule of sucrose consists of two "simple sugars" or monosaccharides. In sucrose, a glucose residue and a fructose residue are linked by an 1→2-α,β-glycosidic bond. Sucrose's empirical formula is C₁₂H₂₂O₁₁, and its systematic name is α-D-glucopyranosyl-(1→2)-β-D-fructofuranoside.

Composition

Diagram illustrating structure of the sucrose molecule

Sucrose is a disaccharide composed of one molecule of glucose connected via an α(1-2) glycosidic bond to one molecule of fructose.

( α(1-2) pronounced alpha-one-two )

Production

Sucrose is a covalently bonded compound. Sucrose is generally extracted from sugar cane or sugar beet and then purified and crystallized. Other (minor) commercial sources are sorghum and sugar maples.

Crystalline nature

When you add sugar to water, the sugar crystals dissolve and the sugar goes into solution. But you can't dissolve an infinite amount of sugar into a fixed volume of water. When as much sugar has been dissolved into a solution as possible, the solution is said to be saturated.

The saturation point is different at different temperatures. The higher the temperature, the more sugar that can be held in solution.

When you cook up a batch of candy, you cook sugar, water, and various other ingredients to extremely high temperatures. At these high temperatures, the sugar remains in solution, even though much of the water has boiled away. But when the candy is through cooking and begins to cool, there is more sugar in solution than is normally possible. The solution is said to be supersaturated with sugar.

Supersaturation is an unstable state. The sugar molecules will begin to crystallize back into a solid at the least provocation. Stirring or jostling of any kind can cause the sugar to begin crystallizing.

Sucrose melts and decomposes at 186 °C to form caramel, and when burnt produces carbon dioxide and water.

Usage

Pure sucrose is the most common sweetener in the modern, industrialized world. People, and in fact most other mammals except members of the cat family, will gladly accept a food sweetened with sucrose, even if they aren't hungry. Processed food and junk food often have sucrose added.

In the human digestive system

Sucrose is broken down in the gut into its component sugars which are then absorbed into the bloodstream through the intestine, which means this disaccharide can offer a fast sugar boost.

Health effects

Sucrose has been linked with some adverse health effects. The most common is tooth decay, in which bacteria in the mouth turn convert sucrose in food producing acids that attack tooth enamel. Sucrose has a high food energy content and in a poorly managed diet can contribute to obesity. People with diabetes mellitus need to control their intake of sucrose along with the other carbohydrates.

Sugar substitutes

Because of the perceived health issues and the cost of sucrose, several substitutes have been developed, although none have the full functionality of sucrose in cooking. An intense sweetener, Sucralose, sold as Splenda, is based on sucrose.

Properties

• Solubility in water: about 2.1 g sucrose in 1 g water (at 25 °C).
• Refractive index of 10% solution:
• Melting point:

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