Mannitol
What it does
Sweetener/anti-caking.
How it's made
Made by hydrogenating sugars.
Mannitol is a sugar alcohol (polyol) used as a sweetener, bulking agent and anti-caking dusting powder; it is roughly half as sweet as sugar, low in calories, and notable for not absorbing much moisture, which makes it useful for dusting chewing gum and for sugar-free sweets. It occurs naturally in some plants and seaweeds.
It is produced by hydrogenating sugars — adding hydrogen to fructose or to glucose/fructose mixtures under pressure with a catalyst — which converts them into mannitol (alongside some sorbitol, which is separated off). It can also be made by fermentation using certain microbes that produce mannitol directly.
The mannitol is purified and crystallised into a white powder. Because it dissolves with a cooling sensation, is only partly absorbed, and does not readily take up water, it suits particular applications like dusting sticky confectionery; like other polyols it provides fewer calories, is tooth-friendly, and can be laxative in large amounts.
Possible reactions
Laxative effect in larger amounts.