Organic Chemistry: Concepts and Applications - Headley Allan D. 2020

Synthetic Polymers and Biopolymers
20.16 Disaccharides and Polysaccharides

The glycoside bond is the bond that bonds two or more monosaccharides to form polysaccharides. Glycoside bonds are typically formed at the anomeric carbon of a monosaccharide and the hydroxyl group of another monosaccharide. Shown below are three commonly known disaccharides, maltose, lactose, and sucrose.

Maltose is a disaccharide, which is obtained from the partial hydrolysis of starch. Complete hydrolysis of maltose gives only one monosaccharide, D-glucose, which implies that there are two glucose monosaccharides in maltose. Lactose is a disaccharide consisting of galactose and glucose. Lactose makes up about 2—8% of milk, but lactose cannot be absorbed by some individuals, and there is a buildup of this disaccharide in the blood and urine of these individuals, which is called galactosemia (or lactose intolerant). On the other hand, sucrose contains no galactose (just glucose and fructose). Sucrose is often added to candy to give it a smooth and creamy texture. In the manufacture of candy, sucrose will disrupt the slow cooling crystal formation process of the crystallization of candy and the result is smooth and creamy candies.