The cassava root is long and tapered, with a firm, homogeneous flesh encased in a detachable rind, about 1 mm thick, rough and brown on the outside. Commercial cultivars can be 5 to 10 cm (2.0 to 3.9 in) in diameter at the top, and around 15 to 30 cm (5.9 to 11.8 in) long. A woody vascular bundle runs along the root's axis. The flesh can be chalk-white or yellowish. Cassava roots are very rich in starch and contain small amounts of calcium (16 mg/100g), phosphorus (27 mg/100g), and vitamin C (20.6 mg/100g). However, they are poor in protein and other nutrients. In contrast, cassava leaves are a good source of protein (rich in lysine), but deficient in the amino acid methionine and possibly tryptophan.
Cassava is the third-largest source of food carbohydrates in the tropics, after rice and maize.
Cassava is a major staple food in the developing world, providing a basic diet for over half a billion people.
Nigeria is the world's largest producer of cassava, while Thailand is the largest exporter of dried cassava.
The nutrient composition found in Cassava differs according to soil conditions, variety, environmental factors and climate. 100 gm of Cassava provides 1.8 gm dietary fiber, 1.36 gm protein, 16 mg calcium, 27 mg phosphorus, 20.6 mg Vitamin C and others.
Cassava roots, peels and leaves should not be consumed raw because they contain two cyanogenic glucosides, linamarin and lotaustralin. These are decomposed by linamarase, a naturally occurring enzyme in cassava, liberating hydrogen cyanide (HCN).
Cassava's Behavior & Ecology
Cassava plant is native to South America. In Maldives it is mainly cultivated in homesreads. Cassava plant is an herbaceous and perennial plant growing upto 3-5 m in height. It bears dark green leaves which measure a foot in across and possess small sized greenish-yellow flowers. It grows best in tropical climate and thrives in moist, fertile and well-drained soils. The plant possesses the fibrous and reddish brown bark with the smooth erect stem. The plant yields the light yellow, white and dark brown fruit of subglobose ellipsoid shape with 1 cm (1/2 inch) as a diameter. The Cassava plant lives upto one year.
Cassava's Relationship with Humans
Cassava root contains twice as much starch as potatoes. In Maldives, cassava is being used in many recipes. In its native habitats it is a major component of the daily diet. Cassava can be thinly sliced and deep fried like potato chips. Bags of these chips are sold as snacks in South America. Dried and ground the root provides tapioca starch. This starch is almost neutral in taste and is sold commercially in the form of pearly grains or as flat bread. The West African and Southeast Asian cuisines, in particular, use soaked tapioca pearls to bind sweet dishes. Brazilians make them into a type of pancake which they eat with butter, coconut milk and cheese. The animal feed industry uses tapioca as a source of carbohydrate which also stops feed pellets from disintegrating. In its native habitats, folk medicine uses fresh cassava root to heal sores and burns.