Carbohydrates - value and Functions in Human Nutrients

CARBOHYDRATES

Carbohydrates are sugars or polymers of sugars such as starch, that can be hydrolyzed to simple sugars by the action of digestive enzymes or by heating with dilute acids.

Carbohydrates are classified as monosaccharides or simple sugars (glucose, fructose), disaccharides or double sugars (sucrose, lactose) and polysaccharides which include many molecules of simple sugars (starches, dextrins).

Functions

The body uses carbohydrate as a source of energy. One gm of carbohydrate provides 4 kilocalories.

They are the major source of energy for muscular work.

The main source of energy for the central nervous system is glucose.

The body mainly uses carbohydrate as the source of energy, thus sparing the tissue protein breakdown for energy purpose. This is called 'protein sparing action of carbohydrates'.

In the liver, carbohydrates have special functions to perform. They include detoxifying action and a regulating influence on protein and fat metabolism.

The heart muscle mainly uses glucose as a source of energy.

Excess of calories is stored in the form of fat in the adipose tissue.

Consumption of indigestible polysaccharides or fibre prevents constipation and reduces the incidence of heart diseases, diabetes mellitus and colon cancer.

FOODS CARBOHYDRATE %

RICH SOURCES        

Sugar, jaggery,     85 - 99

Cereals and millets         63 - 79

Dried fruits 67 - 77

GOOD SOURCES      

Pulses         56 - 60

Milk powder , full fat     38 - 39

Milk powder, skimmed  54 - 55

Roots and tubers  22 - 39

FAIR SOURCES         

Fresh fruits 10 - 25

Milk  4

Nuts and oil seeds          10 - 25