Lorraine L. Niba, MSc.[1]
Department of Nutrition & Food Science
3304 Marie Mount Hall

Fatimah L. C. Jackson, Ph.D.
Department of Anthropology, 1111 Woods Hall

University of Maryland, College Park, Maryland 20742

[1]Author to whom correspondence should be addressed.

INTRODUCTION

Tapioca root (Manihot esculenta Crantz) is probably the most important food crop in tropical and sub-tropical regions.of the world. It constitutes the major source of dietary energy for over 500 million people (Cock, 1985; Jackson & Jackson, 1990). It is estimated to provide approximately 37% of the food calories consumed in Africa, 11% in Latin America and 6% in Asia (Lancaster et al., 1982). 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 AND TAPIOCA FLOUR

Production of tapioca root is geared towards domestic consumption and exportation. Brazil produces about 25 million tons of tapioca root per year for domestic consumption and export. Nigeria, Indonesia and Thailand also produce large amounts of tapioca root for export. (CIAT, 1993). Overall production of tapioca root in Africa was estimated at 85.2 million tons in 1997, while in Asia, it was 48.6 million tons, and 32.4 million tons in Latin America and the Caribbean (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. Portuguese settlers in Brazil initially spread cultivation of this crop from Brazil to central Africa, and later European settlers promoted its use as an effective defense against famine (FAO, 1998, Lancaster et al., 1982, Kahn, 1989; Jackson 1990).

Tapioca flour is the flour obtained from milling the dried root. A range of processing techniques are employed to produce tapioca based foods and beverages. In addition, it finds use as animal feed, in textiles and as raw material in beer brewing.

TAPIOCA ROOT AND ITS UTILIZATION:

The utilization of tapioca root and tapioca flour is relatively rudimentary, primarily because of the general lack of cultural familiarity with this crop outside of the producing regions. Furthermore, consumption of tapioca root has been associated with chronic cyanogenic glycoside toxicity (Jackson, 1991 Mlingi et al., 1992).

Fresh roots contain about 60 - 70.25% 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).

Traditional processing methods do vary immensely from region to region. They include peeling, soaking, chipping, grating, pressing, milling, drying, stacking and fermentation, most of these being adaptations of yam-processing techniques (Hahn, 1989). These methods are generally geared towards products that have the preferred taste, flavor and texture and are safe for consumption (Koch et al., 1994). Tapioca root is processed in the wet or dry form to starch or flour or to paste-like foods. In wet processing procedures, the root may be fermented prior to processing.

Table 1: Traditional Processing of Tapioca Root[*]

Area / Country	Processing Method	Food Product
Africa (Ghana, Tanzania, Uganda, Zaire)	sun dried, ground	flour, kokonte, cossette, unga, chinyanga, makopa, kivunde, udilimbe, malwa
Africa (Ghana, Cameroon, Nigeria)	soaked, boiled, pounded	water-fufu, paste (dumpling) akpu, agbalima
Africa (Cameroon, Cote d'Ivoire, Nigeria, Zaire)	grated, fermented	baton de manioc, bobolo chikwangue, mboung, placali
Africa (Ghana)	boiled, steamed	ampesi
Africa (Liberia)	dried, slurried	depa
India	boiled	incorporated in curry
Indonesia, Nigeria	soaked, shredded, dried	oyek, abacha
Indonesia	steamed, dried	kripik
Latin America	grated, washed	cassareep, beer, dumplings
Latin America	starch extraction	tapioca pudding, sipipa
Latin America (Brazil) Africa (west and central)	crushed, fermented, fried/baked	polvilho azedo, gari, attieke
L. America, Africa (Liberia, Nigeria)	fermented, baked or dried	farinha, Lafun
Philipines	grated, winnowed	cassava rice (landang)
South Pacific (Solomon Islands)	grated (with banana)	pudding
South Pacific(Tikopia)	soaked	ma manioka

[*](sources: Dixon, 1979; Lancaster el al., 1982; Hahn, 1989; Jackson, 1990; Nweke, 1994).

A primary concern in the processing of tapioca root is the detoxification of the cyanogenic glycosides present in the root. Tapioca root is known to contain between 2 - 395 mg of linamarin/100 kg of fresh root (Bradbury & Egan, 1992; Yeoh & Truong 1993). These levels vary among species - leading to the appellations sweet and bitter varieties. In the intact root, the linamarin is separated from its hydrolyzing enzyme, linamarase which is located in the cortex of the root. With crushing, however, it is brought in to contact with the substrate, linamarin, which is then hydrolyzed to acetone and hydrogen cyanide. Hydrogen cyanide is heat labile and also water-soluble. Traditional processing methods which included fermentation and sun-drying significantly reduced cyanogenic glycoside levels (Kemdirim et al., 1995). These methods resulted in reduction of total cyanogens in fresh roots from 91 - 1515 mg/kg to 0.0-11.3 mg/kg, in the prepared foods (O'Brien et al., 1992). Hydrogen cyanide is volatile and crushing to promote cyanogenesis and then release of hydrogen cyanide actually results in a sweeter product since the glucose remains behind (Jones, 1998).

TAPIOCA FLOUR: PRODUCTION AND UTILIZATION

Tapioca flour is the product obtained from milling the dried, raw tapioca root (FAO, 1998). It has also been defined as " the starchy substance extracted from the root of the cassava plant" (Herbst, 1997). The root may be chipped or sliced, dried and then milled into flour, using roller mills, ball mills or hammer mills (Badrie & Mellowes, 1992; DeFloor & Delcour, 1993). The root is sometimes fermented prior to milling. Parboiling of tapioca root chips prior to milling into flour has been suggested to improve the pasting properties of tapioca flour (Raja & Ramakrishna, 1990). Even though grains are the primary source of flour in food applications such as bread making, pastas and breakfast foods, there is evidence that tapioca flour has been used for breadmaking in the Caribbean for several generations(Sokolov, 1992).

Table 2: Tapioca Flour/Tapioca Starch Food Products[*]

Area of Consumption/ Origin	Tapioca flour/ starch based	Product
Caribbean (Jamaica)	Tapioca starch, dried, cooked	Dumplings
Caribbean	Tapioca flour (baked)	Spicy cakes
India	Tapioca flour (groundnut meal, semolina, extruded)	Tapioca macaroni
Indonesia, Malaysia Asia	Tapioca flour (gelatinized, baked)	Tapioca fancies, pearl tapioca, grist
Indonesia, Malaysia, Philippines	Tapioca flour(made into chips)	Kroepeck, krupuk, ca- charon
Latin America, Caribbean	Tapioca starch residue, baked	Sipipa, (crispy cakes)
Latin America (Brazil)	Tapioca starch, cassava flour (extruded, processed)	Fast food, sour starch (Polvilho azedo)
Malaysia	Tapioca starch (composite with wheat)	Sweetened and unsweetened biscuits
N. America, Canada	Tapioca starch/ flour (Baking)	Composite in baked products
N. America, Canada	tapioca starch, gelled	Tapioca pudding
Philippines	Tapioca flour (battered, fried	Bibingka (pancakes)
Philippines	tapioca flour, gelled	Cassava rice
Puerto Rico	Tapioca flour (steamed with plantain flour)	Alcapurrias
South America (Colombia), Caribbean	Tapioca flour (baked)	Cassava bread, tipi
South Pacific, West Africa, Latin America, Asia	Tapioca starch (pregelatinized, dried)	Tapioca meal

[*](sources: de Caloni & Cruz-Cay, 1983; Oyewole & Obleze, 1995; Demiate et al., 1997; FAO, 1998)

As noted earlier, tapioca root is processed into tapioca flour for several reasons including the prolongation of shelf-life, detoxification via removal of cyanogenic glycosides (crushing, heating), improving palatability and possible improvement in nutritional quality. Tapioca flour is available in several forms including granules, flakes, pellets and plain flour. It is used as a thickener in soups among other uses.

POTENTIAL APPLICATIONS OF TAPIOCA FLOUR:

Traditionally, tapioca bread is baked by toasting tapioca root pulp on a griddle and is known as cassava bread, casabe, beigu or couac in the Caribbean (FAO, 1998). However, other kinds of tapioca flour bread are being made now with the inclusion of composite flour such as soybean and peanut flour. Composites, with high protein flour such as soybean flour and wheat bran have been shown to improve extrusion properties and functionality of tapioca flour (Badrie & Mellowes, 1992).

Tapioca flour is popular in the food industry due to its special characteristics - clarity of appearance, low flavor overtones and ideal viscosity. It has been tested as a filler in comminuted meat products.(Annor-Frempong et al., 1996).

With the expansion of the food industry and increase in nutritional needs of the tapioca - consuming populations, tapioca flour and tapioca starch are just being examined for optimization and greater utilization. Some newly tested applications of cassava flour in recent years have been as weaning foods, as substrates in alcohol production and for glucose syrup production (Adewusi et al., 1992; Vuilleumier, 1993; Pontoh & Low, 1995)

WHAT MORE NEEDS TO BE DONE?

The production of tapioca root to meet domestic consumption and industrial demands needs to be optimized. Even though tapioca root crop requires minimal maintenance to survive and as such has year round availability, there is still room for improvement. It has been shown that yields of 5 - 20 tons per hectare can be increased to over 60 tons per hectare with proper attention (FAO, 1998). There is urgent need for the development of pest resistant varieties of tapioca root that do not contain high levels of cyanogenic glycosides. In addition, food processing and packaging techniques ought to be improved to ensure the continued viability of this widely consumed food crop.Trade in tapioca root is a major source of income for producing countries. It is exported in the form of chips, pellets and flour.

Preliminary assessment of market brands of tapioca flour show great variability. Processing techniques therefore need to be standardized in order to obtain consistent and reliable products. Legislation that addresses tapioca flour and tapioca flour products in the market is also required.

Tapioca flour and tapioca starch have been shown to possess desirable characteristics in the food industry. In addition, commercial brands of tapioca flour contain up to 12% fiber. Significant research into food product development of tapioca based foods is certainly imperative. Such foods can be employed in instance of metabolic disorders, as fat substitutes and other such value-added products. Presently, they are mostly found in ethnic food stores and the like. Research efforts would probably result in greater availability and mainstreaming of tapioca based products. Keeping quality of these products would also have to be established.

REFERENCES / BIBLIOGRAPHY

Adewusi SR, Orisadare BO, and Oke OL (1992). Studies on Weaning Diets in Nigeria: Two Protein Sources. Plant Foods Hum. Nutr. 42(2): 183-192.

Annor-Frempono IE, Annan-Prah A, and Wiredu R (1996). Cassava as a Non- Conventional Filler in Comminuted Meat Products. Meat Science. 44 (3) 193-202.

Badrie N and Mellowes, WA (I 992). Cassava Starch or Amylose Effects on Characteristics of Cassava (Manihot esculenta Crantz) Extrudate. Journal Food Science 57 (1): 103-107.

Bradbury JH, Ecan SV, and Lynch MJ (1991). Analysis of Cyanide in Cassava Using Acid Hydrolysis of Cyanogenic Glycosides. Journal Science Food Agriculture 55

CIAT (1993). Cassava: The Latest Facts About an Ancient Crop. Cali, Colombia: CIAT 1993.

Cock, JH (1985). New Potentials for a Neglected Crop. Colorado, US.

DeFloor I and Delcour JA (1993). Impact of Milling Procedure on Breadmaking Potential of Cassava Flour in Wheatless Breads. Cereal Chemistry 70 (5): 616-617.

Demiate IM, Sanger SA, Vocler Z, Cereda MP and Woziacki G (l 997). Characteristics of Quality of Sour Starch Samples Produced or Commercialized in Parana State. Arq. de Biol e Tech 40 (2): 321-300.

Dixon JA (1979). Production and Consumption of Cassava in Indonesia. Bulletin of Indonesia Economic Studies. Nov., 1979.

Eggleston G, Omoaka PE, and Ihedioha DO (1992). Development and Evaluation of Products from Cassava Flour as New Alternatives to Wheaten Breads. Journal Science Food Agriculture 59: 377-385.

FAO. (1998) Food Outlook. Rome: FAO.

Hahn K (1989). An Overview of African Traditional Cassava Processing and Utilization. Outlook on Agriculture, v. 18 (3).

Herbst ST (1997). The Food Lovers Companion; 2nd ed. Barron Educ. Services Inc.

Jackson LC, Bloch EF, Jackson RT, Chandler JP, Kim YL, and Malveaux FJ (1985). Influence of Dietary Cyanide on Immunoglobulin and Thiocyanate Levels in The Serum of Liberian Adults. Journal Natl. Med. Association 77 (10): 777-782.

Jackson, FLC and Jackson RT (I 990). The Role of Cassava in African Famine Prevention. Food Nutr. Hist Anthropol. 7: 207-225.

Jackson FLC, Jackson RT, Delumen BO, Sio FK, Dinkins L, and Muhammad AFH. (1992). Cassava (Manihot esculenta) in Liberia: History, Geography, Traditional Processing, and Cyanogenic Glycoside Levels. Ecology of Food and Nutrition v. 28: 227-242.

Jones DA (1998). Why are so many Food Plants Cyanogenic? Phytochemistry 47 (2): 155-162.

Kemdirim OC, Chikwu OA, and Achinewhu SC (1995). Effect of Traditional Processing of Cassava on the Cyanide Content of Garl and Cassava Flour. Plant Foods Hum. Nutr. 48 (4): 335 - 339.

Koch BM, Sibbesen O, Swain E, Kahn RA, Liangchen D, Bak S, Halkier BA, and Lindberg M (1994). Possible Use of a Biotechnological Approach to Optimize and Regulate the Content and Distribution of Cyanooenic Glycosides in Cassava to Increase Food Safety. Acta Hortic. 375.

Lancaster PA, Ingram JS, Lim MY, and Coursey DG (I 982). Traditional Cassava- based Foods: Survey of Processing Techniques. Economic Botany 36 (1): 12-45.

Mlingi NLV, Poulter NH, and Rosling H (1992). An Outbreak of Acute Intoxications from Consumption of Insufficiently Processed Cassava in Tanzania. Nutrition Research (12): 677-687.

Mlingi NLV, Bokanga M, Kavishe F, Gebre-Medhin M, and Rosling H (1996) Milling Reduces the Goitrogenic Potential of Cassava. International Journal Food Science Nutrition 47 (6): 445-454.

Nweke FI (1994). Processing Potential for Cassava Production Growth in Africa. COSCA Working, Paper No. 11.

O'Brien GM, Mbome L, Taylor AJ, and Poulter NH (1992). Variations in Cyanogen Content of Cassava During Village Processing in Cameroon. Food Chemistry 44 (2): 131- 136.

Oyewole, O.B. and Obieze N (1995). Processing and Characteristics of Tapioca Meal from Cassava. Trop. Science 35: 401-404.

Pontoh J and Low, NH (1995). Glucose Syrup Production from Indonesian Palm and Cassava Starch. Food Research Int. 28 (4): 379-385.

Raja KCM and Ramakrishna SV (1990). Compositional and Pasting Characteristics of Plain-Dried and Parboiled Cassava (Manihot Esculenta Crantz). Food Chemistry (38): 79-88.

Sokolov R (1992). America's First Food Writer- Columbus described the Preparation of the Cassava Bread That is Still Baked in the Caribbean. Nat. Hist. 101 (10): 68-71.

Vuilleumier S (1993). Worldwide Production of High Fructose Syrup and Crystalline Fructose. American Journal Clinical Nutrition 58(5 suppl) 733S - 736S

Yeoh H and Truong V (1993). Quantitative Analysis of Linamarin in Cassava Using a (-Glucosidase Electrode. Food Chemistry 47: 295-298.

Updated: Thursday, September 6, 2007.