Biomolecules in the Cell > Carbohydrates - Fructose

Fructose is another commonly known monosaccharide having the same molecular formula as glucose. It is levorotatory and a ketohexose. It is present abundantly in fruits, and hence it is also called fruit sugar.

Structure of Fructose:

Open Chain Structure	Ring Structure
	\[\alpha\]-D-(-)-Fructofuranose	\[\beta\]-D-(-)-Fructofuranose

Preparation of Fructose:

• From hydrolysis of cane sugar (sucrose): 
  \[ \underset{\text{Sucrose}}{\mathrm{C}_{12}\mathrm{H}_{22}\mathrm{O}_{11}} + \mathrm{H}_2\mathrm{O} \xrightarrow{\text{Dil } \mathrm{H}_2\mathrm{SO}_4} \underset{\text{Glucose}}{\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6} + \underset{\text{Fructose}}{\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6} \]

• From inulin: 
  \[ (\mathrm{C}_6\mathrm{H}_{10}\mathrm{O}_5)_n + n\mathrm{H}_2\mathrm{O} \xrightarrow{\text{Dil } \mathrm{H}_2\mathrm{SO}_4} \underset{\text{Fructose}}{n\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6} \]