Engineering Research to Improve Cassava

Volume 3, Issue 6 2007 Article 9

International Journal of FoodEngineering

Engineering Research to Improve CassavaProcessing Technology

Oladele Peter Kolawole, International Institute of TropicalAgriculture

Leo Ayodeji Sunday Agbetoye, Federal University ofTechnology, Akure, Nigeria

Recommended Citation:Kolawole, Oladele Peter and Agbetoye, Leo Ayodeji Sunday (2007) "Engineering Research toImprove Cassava Processing Technology," International Journal of Food Engineering: Vol. 3 :Iss. 6, Article 9.Available at: http://www.bepress.com/ijfe/vol3/iss6/art9DOI: 10.2202/1556-3758.1311

©2007 Berkeley Electronic Press. All rights reserved.

Engineering Research to Improve CassavaProcessing Technology

Oladele Peter Kolawole and Leo Ayodeji Sunday Agbetoye

Abstract

Cassava is an important food crop, and equipment development for processing it in thedeveloping world requires more research as industrial processing of cassava is still limited.Research efforts made by local engineers need scientific improvement to meet the MillenniumDevelopment Goals (MDGs), aimed at poverty reduction over a stipulated period of time withglobally defined measurable indicators of progress. The World Summit on SustainableDevelopment (WSSD), the Report of the Commission for Africa (popularly referred to as theTony Blair Report), and the New Partnership for African Development (NEPAD) are targeted atre-positioning Africa in the world economy. The need for rapid cassava processing equipment andnew equipment development to significantly improve stages involved in its production process ishighlighted in this paper.

KEYWORDS: high quality cassava flour, food security, Millennium Development Goals(MDGs)

Author Notes: The authors wish to acknowledge the support of Dr. Dixion A., Prof Ogunlowo A.S., Dr Sanni L., Ilona P., and Bamkefa B.

1. Introduction

Nigeria in Africa is the largest producer of cassava in the world. Its production is currently estimated at about 49 million tones a year. Total area harvested of the crop in 2001 was 3.1 million ha with an average yield of about 11 t/ha. Cassava plays a vital role in the world food security because of its capacity to yield under marginal soil conditions and its tolerance to drought. It is the most widely cultivated crop in Nigeria and smallholder farmers who depend on seasonal rainfall grow it.

Cassava provides the livelihood for over 30 million farmers and countless processors and traders. Cassava performs five main roles: famine reserve crop, rural food staple, cash crop for urban consumption, industrial raw material, and foreign exchange earner, also that Nigeria is the most advanced of the African countries poised to diversify the use of cassava as a primary industrial raw material in addition to its the role as livestock feed. Two factors were identified for Nigeria situation: the rapid adoption of improved cassava varieties and the development of small-scale processing technologies.

Despite this development, the demand for cassava is mainly for food; and opportunities for commercial development remain largely undeveloped. Cassava production exhibits high levels of variability and cyclical gluts, due mainly to the inability of markets to absorb supplies. As a result, prices of storage roots decline sharply and production levels are reduced in succeeding years before picking up again. Such factors were identified by IITA as cause of price instability over the years, which significantly increase the income risk to producers. Insufficient processing options and equipment for the processing and storage leading to inadequate marketing channels, and a lack of linkages between producers and the end-users are major factors preventing greater profitability for producers and processors. There is a potential to generate from one crop multiple economic benefits through improved post harvest handling and processing. Major constraints are technical, resources, socio-economic and organizational.

1.1 Cassava Principal Products Cassava could be transformed into two principal products, flour and gari from new and traditional varieties, the new varieties give higher yields only when harvested early (Johnson and Masters 2004), where as traditional varieties could be stored in the ground and harvested as needed for home consumption. Mechanization allows farmers to process large quantities quickly before they spoil. People in the less developed countries of the world depend largely on these food products. And the processing in all cases requires the removal of water, which is about 70% of any giving tuber. Dewatering in cassava processing

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Kolawole and Agbetoye: Engineering Processing of Cassava

Published by Berkeley Electronic Press, 2007

requires engineering attention like any other stages, to make cassava processing more lucrative and competitive all critical stages must be made simple, the most critical processes in cassava processing towards flour production is the juice extraction in that it influences greatly the cost of drying. Dewatering is a pre-drying alternative (Sinha et al., 2000). This operation is mainly carried out manually under rural conditions. This is not only tasking and ineffective, but also time consuming. 1.2 Handling and Processing Handling and processing conditions often result in a very poor quality of the products. In addition to the high labour intensity and drudgery, the conditions during processing are generally unsanitary and unwholesome. During processing by women in rural areas, losses of some mineral and vitamin value do occur (FOA, 1994). This can be avoided with better-designed equipment (Kolawole et al 2007).

In the provision of good food, Cassava processors are now responding to the growing urban demands for food that are more convenient such as bread made with cassava flour, this flour made with cassava need a better method of production, this can only be possible by the use of good machines, which translates to reduction of human effort, improve timeliness and quality of various operations. The global economic changes, in particular the downswing in the world economy with its accompanying effects on developing countries, have increased the importance of cassava processing as an occupation in Africa based on local processing technology available. Cassava is a crop that deteriorates quickly, the processing must be fast and this can only be achieved by the use of well-developed machines. It also contains toxins, its processing consists of four different stages; each stage exposes the workers to various occupationally related ailments, which range from accidental physical and biological injuries, fatigue, cramps and irritation, to cyanide exposure and disorders of ergonomic origin. These aspects of cassava processing have been found to be hazardous to the health of the dewatering operators. (Fajemilehin and Jinadu 1992). Occupationally related ailments are the most common among the cassava graters and dewatering workers, each beings at risk of suffering from at least four different ailments. 1.3 Roles of Science, Engineering and Technology Bamiro (2006) has articulated the key role of engineering and the ways in which it can be developed to achieve the identified goals of development in Africa. Notable projects, programmes, declarations etc. addressing development of Africa

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International Journal of Food Engineering, Vol. 3 [2007], Iss. 6, Art. 9

http://www.bepress.com/ijfe/vol3/iss6/art9DOI: 10.2202/1556-3758.1311

are: the Millennium Development Goals (MDGs), aimed at poverty reduction over a stipulated period of time with globally defined measurable indicators of progress; the World Summit on Sustainable Development (WSSD); the Report of the Commission for Africa (popularly referred to as the Tony Blair Report); and the Partnership for African Development (NEPAD) targeted at re-positioning Africa in the world economy. The Johannesburg Plan of Implementation (JPOI) of WSSD identified during the Summit process, the three pillars of sustainable development as the economic, environmental, and social pillars, and emphasized the fact that ‘science and technology must be placed at the heart of policies to promote sustainable development’. It is shown in that many of the means of implementation of the development initiatives are not related to science and technology policies only but, in reality, to science, engineering, technology and innovation (SETI). Two broad categories of technological capabilities for development was identified: one, the firm/enterprise-level technological capability (FLTC) based on the technology of the firm, comprising six elements of capabilities that firms and enterprises must acquire in varying degrees to meet the challenges in the local and global market place; and two, the national level technological capability (NLTC) which defines the environment within which firms and enterprises operate, and has as its elements – the capital goods manufacturing capability, the educational and training infrastructure for the production of the requisite technological manpower, the techno-managerial consultancy service capability to handle project packaging, the Research and Development capability for innovative development of products and processes, the financial infrastructure, and the S & T information infrastructure leveraging on the existing information and communication technology (ICT) infrastructure available.

1.4 Innovation Capacity In most discussions of technology in relation to development, reference is made in most cases to science and technology (S & T) or scientific and technological capacity while engineering capability is hardly ever formally admitted. Product innovation is really a trilogy of Science, Engineering and Technology (SET). Science designates man's organized attempts to comprehend how things work as causal systems. Science creates understanding that it is neutral, but man to invent or improve or create technology may use that understanding.

Scientific capability or “know-why” is acquired through research and its acquisition from whatever sources - domestic or foreign - can take place meaningfully only if there exists a critical mass of scientific manpower in the our countries - within firms and/or in national R & D institutions. There is some

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scientific capacity in Africa. While science essentially aims at understanding how things work, technology relates to ways of doing things ("know-how").

Technological capability or know-how has always been in existence in any human society. What varies is the level and intensity of its transformation of materials into goods and services most especially on a scientific basis, recognizing within the framework of S & T capability building is the crucial role of engineering.

Engineering capability is a critical component, the integration of which is little appreciated. This has come about because engineering is a generic activity designed to solve technological problems. Engineering is the package of actions we take to put technology to work in the production of goods and services. Engineering provides the final vehicle for producing development out of the knowledge provided by technology and, by extension, science. Engineering capability comes into play in the translation of new technologies or processes into plants and processing machinery.

The development of three mutually interacting capabilities - scientific, engineering, and technological (SET) - should be the focus in contemplating technology for development (Bamiro 2007).

2. Review of Cassava Processing Technology The operations involved in cassava processing depend on the end product desired. In general, the processing stages in cassava include peeling, washing, grating, chipping, drying, dewatering/fermentation, pulverization and sieving/sifting and frying/drying. Five distinct operations are involved in producing gari, and these include peeling, grating, fermentation/dewatering or pressing, sieving (or sifting) and frying. Peeling is the first operation performed after the cassava tubers have been harvested. It involves peeling of cassava tuber outer skin with knives, mostly carried out by the women and children. Mechanized peeling is yet to be fully developed due to factors that include the irregularity in the shape of the cassava tuber. Attempts made by engineers, to produce peeling machines (Agbetoye 2005) Perhaps the most successful motorized cassava peeler was exhibited and demonstrated by the Federal University of Technology, Akure, Ondo State University team at the first Nigerian Universities Research and Development fair held in Abuja in October 2004 where the peeler was awarded a prize for outstanding innovative design. That development further enhanced the mechanization of cassava processing.

The next operation after cassava tubers have been peeled is grating. In the olden days, cassava tubers were grated on a piece of galvanized metal sheet, punched with about 3 mm diameter nails leaving a raised jagged flange on the underside. The grating surface is fixed on a flat wooden frame. This method is

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tedious and time consuming and endangers the operator’s fingers. Mechanized cassava graters have been designed and are replacing manual grating in many localities of West Africa. A typical cassava grater consist of a wooden drum rotor of about 250 to 300 mm in diameter, covered with a perforated tin sheet and are usually powered by electric motors or diesel/petrol engines. This saves time and is less injurious to operators.

In the traditional operations, fermentation and pressing (de-watering) are done in one operation. The grated mash is packed inside baskets, jute bags or perforated plastic sacks and left to ferment for 1-4 days. FAO (1998) stated that the duration of this fermentation affects the colour, taste and texture of the gari. After fermentation has been completed, the mash is then pressed to reduce the water content. The traditional method of dewatering grated cassava mash involves tying and twisting the neck of the hessian sack over which heavy stones are placed for one or two days. The fermentation and pressing, takes long period to accomplish. Presently, the common practice with mechanical presses is to use either hydraulic jacks or a bolt screw and plate ram to apply pressure to woven polythene sacks that contain the grated cassava mash. (Babatunde, 1999). It reduces time for dewatering and less accident is likely to occur compared to traditional method where stone can fall on the operator’s leg. A lot of improvement is still required in this regard. A study was conducted (Kolawole et al (2007) to evaluate the parameters affecting the dewatering of cassava mash. The dewatering parameters investigated were pressure drop, face area of the filter medium and mash resistance. The results provides ground for dewatering machine development.

After pressing, the de-watered cassava mash is a solid cake, which has to be broken up and sieved to remove the large lumps and fiber and to obtain homogenous product, uniform particle size is important because it makes for a more uniform roasting of individual particles during frying operation and that, smaller particles takes less time energy in roasting. IITA (1990) mentioned that sieving the final product of gari ensures uniformity of the product. Gari is first sifted after de-watering in order to remove the fibre (un-grated cassava pieces). In the final re-sieving, the product gari, is separated into chaffy, fine, coarse and medium size fractions. This is done after the frying operation. The texture and consistency of processed cassava food product is an important consideration throughout sub-saharan Africa. Frying and bagging are the final operations in gari processing. At village level gari is fried in shallow cast-iron pans. The sieved cassava mash is spread thinly in the pan in 2-3 kg batches. A piece of calabash is often used in stirring the gari on the hot surface of the pan to prevent it from burning until the frying is completed.

Gari frying and Flour drying are complex procedures, which depends on the skill of the operator. The inability to control the temperature; exposure of the

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operator to heat and smoke from the fire; and steam from the wet cassava mash, have been major set back in traditional frying of gari. Continues feeding of mash in flash drying is another. Processing of cassava into its products such as chips and pellets requires machines. Many of the machines are not available in commercial quantities in the market. The development of these machines including their commercial manufacture to feed the rapidly expanding processing factories is essential.

2.1 Need for Innovation

The need for innovative cassava processing technologies is enormous because traditional cassava processing has a number of undesirable attributes. It is time consuming, provides low yields and lacks storage capacities. Many unattractively describe it as drudgery. Cassava processing in Nigeria where the economies are primarily agricultural is a major single consumer of energy, most of the technologies currently in use were not developed with the primary objective of energy efficiency, and in many cases they did not comprise a large share of the final cost of the product. The need to make the agricultural processing more energy-efficient is now receiving attention as we witness sharp increases in the price of fuels.

The International Institute of Tropical Agriculture (IITA) disease resistant varieties of cassava are boosting productivity. One of the newly innovated products by IITA is the High Quality Cassava Flour (HQCF) an unfermented cassava flour and a very good substitute to the imported wheat flour. Cassava flour prepared using traditional methods is often fermented and frequently of poor quality, thus making it unsuitable as a substitute for wheat flour in bakery products. The capital investment requirements for HQCF production minimized by IITA Ibadan with the introduction of a method that makes use of existing equipment used for gari preparation (Onabolu and Bokanga 1998), proved suitable for preparing cassava flour from both sweet and bitter varieties of cassava (IITA, 2004). The technique enables small-scale primary processors produce high quality unfermented cassava flour that meets industrial users' specifications within one day.

The major physical bottlenecks for the IITA process are access to engineering researched processing equipment, power to provide mechanization and reliance on good weather for drying the product. When the government of Nigeria announced the use cassava as a foreign revenue earner, and passed a law that all wheat bread must be made with 10 per cent cassava flour, about saving 40 million dollars was saved annually with stoppage of wheat imports. This lead to steps in increase HQCF production in order to meet the demand for cassava flour, very good developed machines are now needed in every stages of Cassava

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processing (Sanni 2004). IITA has identified the need for a rapid cassava mash dewatering as second major problem after peeling in the production of High Quality unfermented Cassava Flour (HQCF), the second most important rate determining factor after drying and the most tedious operations. (Abass et al., 2003). 2.2 Cassava Dewatering Method All processing need dewatering to bring the best out of cassava, and dewatering is done in Nigeria using various methods (Aribisala 1992). The list of these methods in use for cassava mash dewatering is as follows:

2.2.1 Boulders or logs Involves application of pressure by placing heavy stones or logs on top of the sacks or baskets containing the mash, to completely squeezed water out of the mash requires turning of the mash at intervals. This usually lasts for between 3 – 5 days.

2.2.2 Sticks: This method involves tying the neck of the sack around string sticks in such a way that by twisting the sticks, the sack is gradually tightened thus water is squeezed out. 2.2.3 Parallel Board: Parallel board method provides uniform pressure to mash filled sacks placed between them. The parallel boards are screwed together to create pressure on the sacks. This method takes about 3 – 4 hrs to dewater one bag about 125 kg. 2.2.4 Tree Stumps: Tree stumps method provides support for a wooden beam support inserted between them. Bags of grated mash are placed on the wooden wedges are hammered into the space between the sacks and the tree.

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2.2.5 Chain or String: This involves 2 or 4 long sticks by tying the chain/string at both ends of the sticks, as the chain/string are tied act internal, water is squeezed out of the sacks. This method may last for between 2 and 3 days.

2.2.6 Screw jack: This can either be in the form of a circular press cage holding the fresh pulp or square frame exerting pressure on the sacks. Both types work by moving a heavy circular or square block, which is lowered or raised by means of, threaded shaft. Capacity of this press is 100 kg/batch usually about 1 to 2 hours depending on the frequency of applying pressure. 2.2.7 Hydraulic jack: Some design of press use a hydraulic jack used for cars or lorries to apply pressure to the material being dewatered, usually between pressboards. The hydraulic jack usually 20 to 30 tonne jacks are used. The frame consists of 2 vertical metal posts and steel channel section compared to the screw and other presses it require the least amount of human effort to operate. This method can dewater six sacks (50 kg each) of cassava mash at a time. 2.2.8 IITA wooden press: This press, which was designed in IITA, consists of a rectangular fixed wood with grooves, another rectangular lid and some wedges. As the pressure is applied, on the bagged mash between fixed and movable lid, and wedges inserted the water is being squeezed out. The capacity of this press is 62 kg/batch in eight hours. (Aribisala 1992) 2.3 Engineering Research in Cassava Flour Technology The equipment being used for the production of HQCF are not designed for the product but merely adopted from gari production process, machines, that will further reduce cassava HQCF processing time, and energy are needed. Engineers developed cassava processing equipment will be better than just mere fabrication and IITA is currently seeking solution to these processes. The need and capacity needed to move to higher levels of technology propelled IITA into developing targets for future research. Developments in cassava processing and utilization

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made IITA to put processing technologies and equipment together at low-level technologies mainly for rural and small-scale processing.

To solve the problem of equipment is the need for more engineering research as no champions of cassava processing equipment in Nigeria to support the equipment users, a lot of variation in the standards of fabricated equipment and their installation nation wide. The scarcity of good machines and the frequent breakdown of these machines were noticed problems looking for engineering solution. The requirements for processing facilities such as chipping machines, dryers, packaging devices, graters, press (screw and hydraulic type), mills, and time saving technologies became important and invention of improved processing equipment are now needed. (IITA, 2004)

Other engineering need is the development of well-defined processing stages that will minimize delays, Currently IITA has established many factories in south-south, south-west and south-east zones of Nigeria, more are still being constructed, they all need good processing equipment for each stages, essential to the success of cassava industries (Sanni, 2004).

The existing cassava flour processing technologies are not energy-efficient to accelerate Nigerian development towards self-sufficiency in cassava flour there is therefore need to improve the existing cassava flour processing technologies by developing a new ones. The local method of flour processing exposes the product to dust and foreign matter contaminations, losses due to rodents’ birds and other domestic animals. Effective innovation and development of these stages that are economically viable and still simple and hygienic will be from engineering research efforts such that little rearrangement by engineers could lead the way for automation. 3. Cassava Processing Machines In Nigeria The development of cassava processing machines is critical for efficient mechanization of its production in Nigeria Furthermore; there is no existing complete process line for any of the cassava products in the market. These problems can only be solved through a collaborative work among all the “stakeholders” (Agbetoye, 2003). The ways out could include the following; a. The design engineers and processors should start all over again from fundamental principles such as studies in mechanisms, engineering properties of roots relevant to tuber damage, development of adequate handling methods to generate design data for processing machines b. Research institutes, educational institutions and government establishments could be empowered to develop machines for cassava processing.

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c. Development of a complete process line for each cassava product. In this regard, the National Agency for Research and Engineering Infrastructures (NARSENI) has begun collaborative work with some Universities for the development of a complete package for cassava processing. d. In developing machines for cassava processing, special attention could be directed at the small-scale farmers who still produce the greatest amount of cassava in Nigeria. For example, a cassava processing handling equipment for HQCF that is powered by a small tractor suitable for small farms and affordable by individuals may be a good starting point for the mechanization. e. The government could provide fund for research in cassava processing mechanization f. Private sectors of the economy could show more interest and commitment in the development of not only cassava processing machines, but also machines for processing other tropical root crops. Cassava deteriorates in quality soon after harvest, and this damage is aggravated when the tubers are bruised, hence the development of mechanized harvesting system should be complemented by adequate farm-processing factory-market transportation system. Even when the tubers are to be processed, adequate measures to ensure their quality preservation must be developed. 4. Conclusion The importance of cassava as source of human food, animal feeds, and source of industrial starch and its increasing economic potential as foreign exchange earner has been substantiated. The problems militating against the development of cassava processing machineries have been identified. Furthermore, the previous attempts made in the mechanization of processing of cassava have been discussed. The roles of the stakeholders towards the achievement of mechanized cassava processing have also been enumerated. 5. References Abass A. Rweyendela V. and Chisawilo P. (2003). Training on Cassava Processing, Market Expansion for Cassava Products, and Development of a Combined Cassava Grater IITA Work Planning Week4–10 Dec. Agbetoye, L.A.S. (2003). Engineering Challenges in Developing Indigenous Machinery for Cassava Production and Processing. Proceedings of the annual conference of the Nigerian Society of Engineers (Lagelu 2003), Cultutral Centre, Ibadan, Oyo State, 8th –12th Dec., 2003.Pp 80-86.

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Aribisalla, A. S. (1992). Methods of Dewatering Cassava Mash; In-Country Training Workshop On Design, Operation and Maintenance of IITA-developed Crop Postharvest Technologies, Conducted under the Auspices of Ford foundations from 27th January to 21th February by Postharvest Unit of IITA-Ibadan. Albertson O., Burris B., Reed S., Semon J., Smith Jr J.E. and Wallace A. (1991).‘Dewatering Municipal Wastewater Sludges’. Pollution Technology Review no 202. Noyes Data Corporation, Park Ridge, New Jersey USA. Babatunde, O.O. (1999). Design of a model dewatering press for gated cassava mash. Journal of Agricultural Technology, 7(2): 8. Bamiro, O. A. (2006). Paper presented at the AERC International Conference on Accelerating Africa’s Development Five Years into the 21st Century, held in Tunis, Tunisia, November 22-24, 2006 Bamiro, O. A. (2007) Lead Paper at the 16th Engineering Assembly of Council for the Regulation of Engineering in Nigeria (COREN), held in Abuja, Nigeria, August 28-29, 2007

Fajemilehin, B.R.and Jinadu M.K. (1992). Occupational Health Hazards Associated with Traditional Methods of Cassava Processing in Nigeria Finnish Institute of Occupational Health, African Newsletter 2/1995 supplement, p.38-39. http://www.ttl.fi/Internet/English/Information/Electronic+journals/African+Newsletter/1995-02/06.htm

FAO (1994). African Experience in the Improvement of Post-harvest Techniques, Food and Agricultural organization of the United Nations, Agricultural Engineering Service (AGSE) Support Systems Division Workshop, Held in Accra Ghana 4th to 8th July, Rome. www.fao.org/docrep/W1544E/W1544E07.HTM FAO, (2000). Cassava An Essential Part of Diet, Championing the Cause of Cassava http://www.fao.org/NEWS/2000/000405-e.htm. FAO, (2002). FAOSTAT, Statistical Data Base of the Food and Agricultural Organization (FAO) Of The United Nations. Rome. Italy Grace M.R. (2003) Cassava Processing, FAO Plant Production and Protection Series No. 3. http://www.fao.org/docrep/X5032E/X5032E00.htm

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Hahn S.K.; Mahungu N.M.; Otoo J.A.; Msabaha M.A.M., Lutaladio N.B., And Dahniya M.T. (1986). Cassava and the African Food Crisis, Tropical Root Crops International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria p. 24-26. IITA, (2006). Flour Power Nigeria. http://www.handsontv.info/series7/programme_4.html IITA, (2004). IITA Annual Report http://www.cassavabiz.org/postharvest/cpc_1.htm Johnson, M. E. And W. A. Masters, W. A. (2004). Complementary and Sequencing of Innovations: New Varieties and Mechanized Processing for Cassava in West Africa, Economics of Innovation and New Technology, Rout ledge, Taylor& Francis Group.Volume13, Number1, Pp.19–31. http://taylorandfrancis.metapress.com/link.asp?id=kmdbkj4w191fa3xx Kolawole O.P., AgbetoyeL.A.S., and Ogunlowo A.S.(2007) Cassava Mash Dewatering Parameters, International Journal of Food Engineering: Vol. 3 : Iss. 1, Article 4. http://www.bepress.com/ijfe/vol3/iss1/art4 Ndaliman M. B. (2005). Development of Cassava Grater: Dual Operational Mode from Leonardo Journal of Science. http://ijs.academicdirect.org/A09/103_110.htm Olukunle O.J. (2005) Development of a Cassava Peeling Machine, Paper presentation as published, Conference on International Agricultural Research for Development Tropentag. Stuttgart-Hohenheim, October 11-13, Onabolu A., AbbassA., and Bokanga M.(2003) New food products from cassava. http://www.cassavabiz.org /IITA Publications. Piotr Lewicki (1984), The Use of Energy in Food Processing and Distribution: Selected Problems, SGGW-AR Agricultural Academy, Warsaw, Poland, and Wlodzimierz Kamiñski, Institute of Agricultural and Food Economics, Warsaw, Poland. Sanni L, (2004), Fabricators of Cassava Processing Equipment Workshop: National Center for Agricultural Mechanization (NCAM),Ilorin, Kwara State Bussiness vanguards. Friday, 24.December http://www.vanguardngr.com/section/law.html

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Engineering Research to Improve Cassava