Fructose

(Chem.) Fruit-sugar; the sugar contained in ripe fruits. It has been called, with reference to its characteristic feature, uncrystallizable sugar, and seems to occur in the transition of starch, cellulose, and cane-sugar, into grape sugar. If, in the manufacture of grape-sugar from starch, by boiling with dilute sulphuric acid, the ebullition be checked as soon as the liquid becomes sweet, fructose is formed and no crystals can be obtained. It forms the chief ingredient in mola es and treacle, for though it is not found in the fresh cane juice, the extraction of the sugar occasions its formation at the expense of cane-sugar.