Isomalt

Isomalt is a natural sugar substitute, a type of sugar alcohol, which is primarily used for its sugar-like physical properties. It has only a small impact on blood sugar levels, does not promote tooth decay, and has one half the calories of sugar. However, like most sugar alcohols, it carries a very real risk of gastric distress, including flatulence and diarrhea, when consumed in large quantities. Isomalt is typically blended with a high intensity sweetener such as sucralose, so that the mixture has approximately the sweetness of sugar.

Isomalt is a disaccharide composed of the two sugars glucose and mannitol. It is an odourless, white, crystalline substance containing about 5% water of crystallisation. Isomalt has a minimal cooling effect (positive heat of solution ), lower than many other sugar alcohols, particularly xylitol and erythritol. Isomalt is unusual as it is a natural sugar alcohol that is produced from beets. An interesting use of isomalt is found in the product DiabetiSweet, a sugar substitute sold for baking use and composed of a blend of isomalt and acesulfame potassium, but it has a bitter taste (due to the acesulfame potassium) and lacks the caramelizing properties of sugar.

Isomalt is manufactured in a two-stage process in which sugar is first transformed into isomaltulose, a reducing disaccharide (6-O-α--glucopyranosido--fructose). The isomaltulose is then hydrogenated, using a Raney metal catalytic converter. The final product—isomalt—is an equimolar composition of 6-O-α--glucopyranosido--sorbitol (1,6-GPS) and 1-O-α--glucopyranosido--mannitol-dihydrate (1,1-GPM-dihydrate).

Isomalt has been approved for use in the United States since 1990. It is also permitted for use in Australia and New Zealand.

Isomalt can be used in sugar sculpture and is preferred by some because it will not crystalize as quickly as sugar.