Sorbitol

Sorbitol is a sugar alcohol with a sweet taste that the human body metabolizes slowly, produced by reducing glucose so that its aldehyde group becomes a primary alcohol group; it occurs naturally in fruits such as apples and other tree fruits and berries, and particularly in the stone fruits of Sorbus trees, for which it is named. Most sorbitol manufactured industrially is derived from potato starch rather than extracted from natural sources, through a glucose reduction reaction catalyzed by aldose reductase. As a food ingredient, designated E420, it provides about half the sweetness of table sugar and supplies less dietary energy than ordinary carbohydrates, between 2.5 and 3.4 kilocalories per gram compared with about 4 for carbohydrates, and it appears in diet foods, diet drinks and ice cream, mints, cough syrups and sugar-free chewing gum. Beyond sweetening, sorbitol functions as a humectant and thickener, and in baking it acts as a plasticizer and slows the staling of baked goods.