Category: sweetener
Aliases: E420, D-Glucitol, D-Sorbitol, Glucitol, (2S,3R,4R,5R)-Hexane-1,2,3,4,5,6-hexol, INS 420
Six-carbon sugar alcohol (hexitol), the reduced form of glucose/fructose. Slowly and incompletely absorbed in the small intestine by passive diffusion; the absorbed fraction is oxidised by hepatic sorbitol dehydrogenase to [[fructose]], which then enters glycolysis — the second limb of the polyol (aldose-reductase/SDH) pathway that also operates intracellularly under hyperglycaemia. Because absorption is slow and partial, it carries roughly half the caloric value of sucrose and a low glycaemic response largely independent of [[insulin]] for its first metabolic steps. The unabsorbed remainder is osmotically active in the colon, drawing water and undergoing bacterial fermentation, which underlies its use as an osmotic laxative and its dose-dependent flatulence/diarrhoea (a FODMAP polyol). About 60% as sweet as sucrose.