Sucrose is a hexasaccharide and has molecular formula C12H22O11.
The structure of shcrose contains glycosidic linkage between C – 1 of α-glucose and C – 2 of β-fructose.
Since aldehyde and ketone groups of both monosaccharide units are involved in the formation of glycosidic bond, sucrose is a nonreducing sugar.
Sucrose is dextrorotatory, on hydrolysis with dilute acid or an enzyme invertase gives equimolar mixture of dextrorotatory glucose and laevorotatory fructose.
The solution is laevorotatory because laevo rotation of fructose (-92.4°) is more than dextrorotation of glucose (+52.50), hence the sign of rotation is changed from (+) to (-) after hydrolysis, the product is called invert sugar.
