Sugarcane and Its Economic Importance

Botanical name: Sacccharum officinarum

Family: Graminee

Parts used: Stem or Canes

Sugarcane is the main source of sugar. Half of the world’s sugar comes from sugarcane.It iscultivated in tropics.It is thought to have originated in the tropics near New Guinea in the pre-Christian.By 327 B.C it had become an important crop in India.It reached Egypt in A.D 641 and Spain in A.D.755.It was introduced into New world by the people of Spain and Portugal. From America,it spreads to the west indies in 1741.The name sugar is derived from Sanskrit word sarkara which means gravel i.e, crude sugar.

Sugarcane plant is a coarse grass, which is quite tall about 10-20 ft. A single plant bears many stems in a tuft. It is a rhizomatous, perennial plant with thick, solid, aerial stem. The stem color is variable from white, yellow, dark green, purple red or violet. It is jointed and internodes are smaller at the base and increase in length, until it terminates in inflorescence. There are present prop or slit roots at the lower nodes to give mechanical strength to the stem. On the nodes axial buds are present. Stem contains colored tissues in which many fibro vascular bundles lie. The inflorescence called an arrow or tarsel. Five different species of saccharum have been identified, which are important in cane breeding. All of them are indigenous to old World.  S.officinarum, S.baberi, S.sinense, S.spotaneum  and S.robustum in which last two species are wild.

Preparation of sugar

Sugarcane stems, after harvesting, are brought to sugar mills. By crushers stem is cut into small pieces and then are allowed to run through three sets of steel rollers. In each expression, the juice is extracted after wetting the canes, which ensures complete extracted sap. The fibrous residue left, which is called bagasse.So obtained sweet juice is dark grayish with many impurities.

Its composition is sucrose, glucose, proteins, gums, organic acids, pectins, ash, minerals, dust particles, cane pieces. The soluble nonsugars are precipitated. This is called clarification. Insoluble substances are removed to purify the juice.

After filtering the solid particles are removed by heating to coating the proteins. Then organic acids are neutralized with lime. In order to precipitate nonsugars, So2, Na2SO3, Co2, are added to the cane juice. So obtained juice is partly purified. Then it is run through filter presses to remove the insoluble particles. So obtained juice is concentrated by boiling in vacuum pans and a thick syrup called massecuite is formed, from which a solid mass of brown crystals separate out and the liquid left is called molasses, which is separated by centrifuges. The refined sugar is packed in gunny bags for transportation.

Economic Importance of Sugarcane

1. Sugar is one of the most valuable products of the plant world obtained from saccharum species
2. It is necessary food for man and it is a perfect food and produces energy.
3. A lot of Sugar is used in the manufacture of alcoholic beverages, soft drinks, ice-creams, chocolates, canning industry, etc.
4. Molasses is an important byproduct of sugarcane industry which is used as a livestock feed and for preparation of rum, industrial alcohol, vinegar, glycerol, lactic acid and monosodium glutamate.
5. Thick noble canes which are soft and have high juice and sugar content and low fiber are chewed throughout the tropics.
6. The molasses is used in cooking and candy making, and sometimes it is used as manure.
7. Bagasse is used as a fuel in sugar mills. It is also used for paper making and as an ingredient of fiber board.