1. Sucrose is an invert sugar: Sucrose (+66.6°) and glucose (+52.5°) are dextro rotatory compounds while fructose is levo rotatory (- 92.4°). During hydrolysis of sucrose, the optical rotation of the reaction mixture changes from dextro to levo. Hence sucrose is also called invert sugar.
2. In sucrose, C1 of α – D glucose is joined to C2 of α – D fructose. The glycosidic bond thus formed is called α – 1, 2 – glycosidic bond. Since both the carbonyl carbons (reducing groups) are involved in the glycosidic bonding, sucrose is a non – reducing sugar.