Question

D-fructose is used for sweetening cold drinks but not hot ones because:

• A. it is not a true carbohydrate
• B. on heating it is converted into pyranose form
• C. on heating it is converted into furanose form
• D. on heating it gets decomposed

Answer 1

Answer: (C)

on heating it is converted into furanose form

The D-fructose exists in two forms, pyranose and furanose forms, in equilibrium. These two forms interchange depending upon the temperature of the system.

The furanose form of fructose is less sweet than its pyranose form and when the temperature is increased, the equilibrium shifts to the furanose structure and this makes the solution less sweet.

Therefore, option C is correct.