Characteristics

Occurrence

Isomalt is a sugar substitute consisting of dissaccharide alcohols. It is derived exclusively from sugar by enzymatic conversion into isomaltulose, which is then hydrogenated to obtain the two component mixture of GPS and GPM.

Appearance

Isomalt is available as a crystallised powder with different granulometries, as a pure syrup and in a liquid blend with a special maltitol syrup in which the content of maltitol and hydrogenated oligosaccharides are balanced.

Molecular structure

Chemically, isomalt belongs to the class of disaccharide polyols like maltitol and lactitol. It is derived exclusively from sucrose.

It consists of two components in a 1:1 ratio, 1,6-glucopyranosyl-D-sorbitol (GPS) and 1,1-glucopyranosyl-D-mannitol (GPM).

Chart 1 - Molecular structure of isomalt

As a consequence of the conversion of the reducing sugar group of the intermediate isomaltulose into an alcohol function during the production of isomalt, the chemical stability is improved and the tendency to undergo Maillard reactions (browning) is substantially reduced. This process also modifies several physicochemical properties such as solubility, viscosity, hygroscopicity and boiling temperature, parameters which differentiate the behaviour of the various polyols.

Molecular weight

Compared to the group of polyols currently used as sweeteners, isomalt like maltitol and lactitol has a high molecular weight of 344.