Sorbitol is a sugar alcohol with a sweet taste which the human body metabolizes slowly. It can be obtained by reduction of glucose, which changes the converted aldehyde group (−CHO) to a primary alcohol group (−C(OH)H2). Most sorbitol is made from potato starch but corn is also a very frequent source. It is converted to fructose by sorbitol-6-phosphate 2-dehydrogenase. Sorbitol is an isomer of mannitol, another sugar alcohol; the two differ only in the orientation of the hydroxyl group on carbon 2. While similar, the two sugar alcohols have different melting points, and uses.

Usage

Sorbitol is a sugar substitute, and when used in food it has the INS number and E number 420. Sorbitol is about 60% as sweet as sucrose (table sugar).

Sorbitol is referred to as a nutritive sweetener because it provides dietary energy: 2.6 kilocalories (11 kilojoules) per gram versus the average 4 kilocalories (17 kilojoules) for carbohydrates. It is often used in diet foods (including diet drinks and ice cream), mints, cough syrups, and sugar-free chewing gum. Beyond its use as a sugar substitute in reduced-sugar foods, Sorbitol is also used as a humectant in cookies and low-moisture foods like peanut butter and fruit preserves. In baking, it is also valuable because of its heat stability and it acts as a plasticizer, and slows down the retrogradation or the staling process. Along with Glycerin and MPG (Mono Propylene Glycol) sorbitol is used in industrial cake and pastry production because of its hygroscopic (Moisture retaining) properties.

Sorbitol often is used in modern cosmetics as a humectant and thickener. It is also used in mouthwash and toothpaste and as solvent in many cough syrups. Some transparent gels can be made only with sorbitol, because of its high refractive index.