About Raw Material – Tapioca Root (Cassava):
In the Encyclopedia Americana, the meaning of the word, “Cassava” is given as follows:
“CASSAVA, kas-sava (also called MANIOC, MANDIOC, YUCA, CASABI), South American shrubs of the genus Manihot, of the spurge family. Euphorbiaceae, widely cultivated in tropical America for their fleshy, starchy roots which form a large part of the food of the natives of northern South America; from the starch, tapioca is made. They have also been introduced into other warm countries specially Africa, and have quickly gained important positions as food crops. Two species are used for their starch content: M. utilissima (also known as M. esculenta) the bitter cassava and M. dulcis, variety Aipa, the sweet cassava. The former, although containing some very poisonous hydro-cyanic acid is much more widely used on account of its greater starch content, the poisonous part being removed during the processing of the starch. The starch content varies from 15 to over 30 percent in contrast to 12-20 percent for potatoes and about 60 percent for maize”
Manihot esculenta Crantz
|Kingdom: Plantae(unranked): Angiosperms(unranked): Eudicots
Species: M. esculenta
(Source: http://en.wikipedia.org/wiki/Cassava )
The cassava or manioc plant has its origin in South America. Its Botanical name is “Manihot Esculenta Crantz Syn. Utilissima”. Amazonian Indians used cassava instead of or in addition to rice/potato/maize. Portuguese explorers introduced cassava to Africa through their trade with the African coasts and nearby islands.
Tapioca Root was introduced in India during the later part of the 19th Century, Now, mainly grown in the States of Kerala, Andhra-Pradesh, & Tamilnadu. Products from Tapioca root like Starch & Sago introduced in India only in 1940s upwards. First by hand manually & later developed indigenous production methods.
Currently, The Tamilnadu State stands first in respect of processing of tapioca into starch & sago, in India. In India, Sago & Starch was produced first in Salem (Tamilnadu). About in 1943-44, Some 50 years ago, sago production started on a cottage scale basis in India by pulping the tapioca roots, filtering the milk-extract and after settling the milk, forming globules and roasting these globules.
Tapioca Root is the basic raw material for Sago and starch. There is about 30% to 35% starch contents generally in Indian tapioca root. India is one of the leading countries in tapioca production. About 650 to 700 units is engaged in tapioca processing in Salem district (Tamilnadu State). It is a very nutritious product as it contains Carbohydrates and appreciable amount of Calcium and Vitamin-C.
This is a well known crop that is recognized by several names in the various regions where it is consumed. It is known as yuca, rumu or manioca in Latin America, manioc in French-speaking Africa and Madagascar, cassava in English-speaking Africa, Ceylon and Thailand, mandioca or aipim in Brazil, tapioca in India and Malaysia, and bi ketella or kaspe in Indonesia (FAO, 1998). Sweet varieties of the crop such as Manihot utilissima Pohl are reported to have lower levels of cyanogenic glycosides, while bitter-tasting varieties exemplified by cultivars such as Manihot palmata Muell and Manihot aipr Pohl are thought to have higher levels of cyanogenic glycosides. These cultivars fall within the species Manihot esculenta Crantz which belongs to the family Euphorblaceae (Dixon, 1979; Lancaster et al., 1982; FAO 1998).
Tapioca root has a high resistance to plant disease and high tolerance to extreme stress conditions such as periods of drought and poor soils.
Fresh roots contain about 60 – 70% moisture, 7 – 12% protein, 5 – 13% starch (32 – 35% total carbohydrate) and trace amounts of fat (Lancaster et al., 1982; Jackson, 1990; FAO, 1998). The high starch and moisture content render it extremely perishable. (Hahn 1989; Mlingi et al., 1996). Processing is therefore indispensable to facilitate preservation, improve palatability and product quality as well as reduce cyanogenic glycoside toxicity (Jones, 1998).
(Source: http://sabuindia.com/sago1.html )
Cassava .. constitute the most important sources of energy in the diet of tropical countries in the world. Cassava is rapidly emerging as a crop of considerable importance in India. Latin America has been reported as the place of origin, where the indigenous population for at least 4,000 years has grown it. After the discovery of America, Europeans soon recognized the advantages of the crop and took the crop to Africa as a potentially useful food crop, later to Asia also to be grown as a food security crop as for the extraction of starch (Howler, 2004).
Cassava was either introduced into Sri Lanka and India by the Portuguese during the 17th century, or it was directly introduced from South America to India in 1840 (Abraham 1956). Kerala and Tamilnadu account for about 80% of the total acreage of the crop in India. India possesses the highest national tuberous root yield in the world (27.6 t ha-1). It is cultivated in an area of 0.2 million ha producing 5.5 million t of tuberous roots. Cassava has the capacity to produce large amount of food calories per unit area, ability to adopt to erratic climatic conditions, resistance to locusts and several pests and diseases. Easy culture, low labour requirement, and cost of production are among some of its unique features that further encourage the spread of its culture to several regions of the country. Besides being important in human diet in Kerala, cassava provides cheap nutritious feed for livestock as well. Its tuberous roots have innumerable industrial uses also, particularly for starch extraction
(source: Recent Trends in Cassava Breeding in India – S G. Nair* and M. Unnikrishnan – Central Tuber Crops Research Institute, Trivandrum, India. http://www.geneconserve.pro.br/artigo037.pdf )
Different Varieties of Cassava (Tapioca Root)
In 1963, the Central Tuber Crops Research Institute (CTCRI) of the Indian Council of Agricultural Research (ICAR) was established for research on tropical tuber crops, with main emphasis on cassava. Achievements in cassava breeding and varietal dissemination in India have since been largely due to the contributions from CTCRI.
High-Yielding Varieties Extensive inter varietal hybridization between superior varieties, and selection among recombinant s resulted in the isolation and release of the first three high-yielding varieties of cassava from CTCRI in 1971.
They are H-97, H-165 and H-226 (Magoon et al., 1970). As the emphasis in breeding was on yield improvement, the culinary quality of those hybrids was not as good as that of the preferred local varieties; hence, they could not establish well as table varieties in Kerala. Nevertheless, they are the most preferred varieties in the neighbouring states. In 1977,two higher yielding hybrids with improved culinary quality were released as Sree Sahya and Sree Visakham (Jos et al., 1981).
H-97 is a hybrid between a local variety and a Brazilian selection. It has conical, short roots, yielding 25-35 t/ha, and has a crop duration of ten months.
H-165 is a hybrid between two local cultivars. The roots are relatively short and conical, yielding 33-38 t/ha. The variety is comparatively early maturing and can be harvested after 8-9 months.
H-226 is a hybrid between a local cultivar and the Malayan introduction, M4. The root yield is 30-35 t/ha, and crop duration is ten months. Both H-165 and H-226 are the predominant varieties cultivated in the states neighboring Kerala. H-226 has a high yield under irrigated cultivation in Tamilnadu.
Sree Visakham is a hybrid between a local cultivar and a Madagascar variety. It has compact roots, which have yellow flesh due to a high carotene content (466 IU/100 g).
Crop duration is ten months, and the root yield is 35-38 t/ha.
Sree Sahya is a multiple hybrid involving five parents, two of which are exotic and three indigenous. The roots are long-necked, yielding 35-40 t/ha. Crop duration is 10-11 months. Both Sree Visakham and Sree Sahya are improved table varieties, having better palatability than the former three hybrids.
Early Maturing Varieties
Over the last two decades the cultivation of cassava as a monocrop in the uplands started to decline in Kerala due to the cultivation of plantation crops which give higher income to the farmers. On the other hand, cassava is more and more being cultivated in low-lying areas after the main crop of rice, and for this short-duration varieties are needed.
The early maturing (7 months) selection, Sree Prakash, released in 1987 (Nair et al., 1988) was quickly adopted in paddy-based cropping systems in the low-lying areas. As cultivation of cassava in low-lying areas started to increase, better short-duration varieties 177 were needed. Sree Jaya and Sree Vijaya are two short-duration varieties which were released in 1988 for this purpose.
Sree Prakash is an indigenous selection. The plants are relatively short with high leaf retention. Its crop duration is 7-8 months and its root yield 35-40 t/ha.
Sree Jaya is a selection from indigenous germ plasm. The plants are medium in height, yielding conical roots with white flesh. Its crop duration is six months and root yield 26-30 t/ha.
Sree Vijaya is a selection from indigenous germ plasm. It has conical roots with yellow flesh and a root yield of 25-28 t/ha. Crop duration is six months.
The three short-duration varieties, having higher yield and excellent culinary quality, are much preferred by the farmers in Kerala, as they are ideally suited to cultivation in low-lying areas as a rotational crop after the paddy harvest.
As the industrial belts of Tamilnadu and Andhra Pradesh are continually in need of cassava roots, the short duration varieties are also becoming popular in those states.
As the role of cassava started changing from a human food item to an industrial raw material in the neighboring states, especially Tamilnadu and Andhra Pradesh, higher yield became the most important factor. As a result, the high-yielding hybrids like H-165 and H-226 quickly dominated the industrial belts of Tamilnadu and Andhra Pradesh.
The demand was for higher dry matter and starch contents. Among the artificially produced polyploids, triploids were found to combine higher yield and higher starch content.
Sree Harsha is the first triploid variety of cassava, released in 1996 (Sreekumari et al., 1999). It is a hybrid between a diploid selection and induced tetraploid of the released variety Sree Sahya. The plants are short, vigorous and non-branching or top-branching. The leaves are broad, thick and dark green in colour. Its roots are very compact, yielding 35-40 t/ha. Crop duration is ten months, but because of its early bulking nature it can be harvested as early as the 7th month without any yield loss or starch reduction in the roots. Sree Harsha has recorded the highest starch content of 39.1% among the released cassava varieties.
Triploids are produced by crossing diploids with colchicine-induced tetraploids.
Use of diploids as female parents was found to be more successful in the production of triploids while reciprocal crosses were unsuccessful. Certain parental combinations were found to be more fruitful in producing triploids.
Triploidy per se was found to be related to a number of desirable attributes in cassava, such as higher yield, higher harvest index, greater dry matter and starch contents in roots, rapid bulking, early harvest ability, shade tolerance and tolerance to cassava mosaic disease (CMD).
The triploid hybrid has made substantial advances in the breeding of cassava as it also combines high yield with excellent culinary quality, making it suitable as a dual purpose variety for both industrial and table purposes. Triploidy breeding in cassava 178 offers enhanced frequency of higher yielders in the progeny compared to other breeding methods, thus providing better opportunities for selection. Being vegetatively propagated but with a sexual reproduction system, cassava is a suitable plant for triploidy breeding.
Although induction of tetraploidy, interploidy crosses, seed set, germination and recovery of triploids are beset with several hindrances, triploid breeding is worth the effort. All practical aspects of triploidy breeding in cassava have been standardized at CTCRI.
Cassava, which is highly heterozygous and cross-pollinated, is also found to be a suitable plant for exploitation of heterosis. Inbred s were produced up to the 5th generation. Although considerable inbreeding depression was manifested in varying degrees for almost all the characters, certain genetic stocks tolerated inbreeding depression to a great extent. Studies show that root yield and most of the yield components in cassava are governed by dominant gene action, suggesting the scope for exploitation of heterosis in cassava improvement. Heterosis for root yield, in different varieties, was found to range from 10-100% over the better parent.
Two superior selections from top-cross hybrids of inbreds with the released variety Sree Visakham (TCH-1 and TCH-2) were found to have very palatable root quality, higher yield (42-44 t/ha), higher harvest index (69-71%) and lower cyanogen content (74-80 ppm). They have been tested in yield trials, on-farm trials and multi-location trials, and are now recommended for formal release (Easwari Amma et al., 2000)