Disaccharide is the most common form of sugar that is found in nature. It results from the combination or reaction of two simple sugars (monosaccharides). It has two types, the reducing and non-reducing sugar. Sucrose is a classic example of a non-reducing sugar.
Sucrose is the technical term for table sugar such as cane sugar or white sugar. It is composed of the combination of one glucose molecule and one fructose molecule.
The process starts with a condensation reaction, a process involving the release of water. This process is followed by the formation of a glycosidic bond between two available and appropriate monosaccharide molecules, creating disaccharides like sucrose.
Sucrose is soluble in water but its molecules are too big to pass through the cell membrane during diffusion. It can only be broken down through a hydrolysis reaction, a reverse condensation reaction.
Reducing capability is defined by the presence of potential aldehyde or ketone group, anomeric carbons found in sugars, which determine a substance’s ability to lose or gain electrons to form new or more stable solutions or its reaction to other substances.
Benedict and Fehling’s reagent are two solutions used to determine the reducing capability of a sugar. These solutions are used to determine the presence of free aldehyde or ketone group in sugars.
The reason that sucrose is a non-reducing sugar is that it has no free aldehyde or keto group. Additionally, its anomeric carbon is not free and can’t easily open up its structure to react with other molecules.