Introduction

Carbohydrates are important constituents of potato tubers. These are defined as aldehydes or ketones of polyhydric alcohols and also include those biopolymers, which yield these compounds on hydrolysis. They occur in animals, plants as well as in microorganisms and perform diverse structural and metabolic roles. Sugars such as glucose are amongst the major sources of energy whereas starch and glycogen function as storage polysaccharides in plants and animals, respectively. In addition, carbohydrates are structural components of cell walls, connective tissues in animals and exoskeletons of invertebrates. They are also constituents of vital biomolecules like nucleic acids, coenzymes such as NAD (P), FAD and many more.

Classification of Carbohydrates

Carbohydrates referred to as saccharides (Greek: Sakcharon, meaning sugar) are classified as follows:

These carbohydrates are a single unit of polyhydroxy aldehydes or ketones and cannot be hydrolysed into simpler compounds. Sugars like arabinose, stachyose, ribose, glucose, fructose, galactose etc. are examples of monosacchardies.

ii) Oligosaccharides

They contain 2-10 units of monosaccharides (monomers) linked to each other via glycosidic linkages, e.g. sucrose, lactose, maltose, raffinose, stachyose etc.

iii) Polysaccharides

Carbohydrates which are composed of more than ten monosaccharide units linked to each other through glycosidic bonds are referred to as polysaccharides. These include carbohydrates like cellulose, starch, glycogen, fructans, arabinans etc.