What is fructose?

Fructose, or fruit sugar, is a sugar which occurs in fruit juices and honey together with dextrose, of which it is an isomer. Fructose (and dextrose) are also obtained by the inversion of cane sugar. Fructose is very slightly sweeter than cane sugar and is used as a sweetening agent in foods used by persons suffering from diabetes. Fructose is prepared on an industrial scale from dahlia tubers and from Jerusalem artichokes. It has been prepared synthetically and is structurally a ketonic alcohol. Fructose crystallizes as hard, anhydrous needles from alcohol and as prisms with one-half molecule of water of hydration from concentrated aqueous solutions. It rotates polarized light to the left and is fermentable by yeast, yielding the same products as does glucose.

Fructose has the formula C6H12C6.