Question

The total number of reducing sugars among the following is:

Answer 1

Carbohydrates having free aldehyde group or free ketone group or comprising hemiacetal form in the structure are reducing in nature.

(a), (c) and (e) are reducing in nature.

(b) does not have a hemiacetal form and so will not act as a reducing sugar.

Anomeric carbons of both the monosaccharides of (d) are involved in glycosidic linkage. So, its chemical structure does not allow the formation of hemiacteal.