A

PROPOSAL SEMINAR

ON

DEVELOPMENT OF AN INTEGRATED PROCESS PLANT FOR PRODUCTION OF POUNDO YAM SMALL SCALE MANUFACTURING INDUSTRIES

BY

OLABANJI OLAYINKA MOHAMMEDMEE/04/3081

SUBMITTED TO

THE DEPARTMENT OF MECHANICAL ENGINEERING SCHOOL OF ENGINEERING AND ENGINEERING TECHNOLOGY

IN PARTIAL FUFILMENT OF THE REQUIREMENTS FOR THE AWARD OF MASTERS OF ENGINEERING (M- ENG) IN MECHANICAL ENGINEERING

THE FEDERAL UNIVERSITY OF TECHNOLOGY, AKUREONDO STATE

DATE

OUTLINE OF CONTENTS

1.0 Introduction

1.1 Objectives

1.2 Methodology

1.3 Statement of Problem

1.4 Contribution to Knowledge

2.0 Literature Review

2.1 Background of the Study

2.1.1 Nutritional value of yam

2.2 The production stages involved in instant pounded yam flour (IPYF) production

2.2.1yam selection and weighing

2.2.2 washing

2.2.3 peeling and slicing

2.2.3.1steam and conventional chemical peeling

2.2.3.2 mechanical knife peeling

2.2.3.3 abrasive peeling

2.2.3.4 dry caustic peeling of root crops

2.2.3.5previous effort on peeling

2.2.3.5.1rotating cage peelers

2.2.3.5.2 u bed design

2.2.3.5.3 ukatu’s industrial yam peeler

2.2.4 parboiling

2.2.5drying

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2.2.5.1 bind

2.2.5.2 cabinet drier (tray drier)

2.2.5.3 tunnel drier

2.2.5.4 conveyor drier (belt drier)

2.2.5.5 fluidized belt drier

2.2.5.6 kiln drier

2.2.5.7 pneumatic driers

2.2.5.8 rotary drier

2.2.5.9spray drier

2.2.6 grinding

2.2.7 sieving and packaging

3.0 Work Plan

4.0 Source of Fund

5.0 Project Evaluation

6.0 Supervision

7.0 Conclusion

References

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1.0 INTRODUCTION

High post harvest food losses, arising largely from limited food preservation capacity are

a major factor constraining food and nutrition security in the developing countries of West

Africa, where seasonal food shortages and nutritional deficiency diseases are still a major

concern (Hulse, 1983)

According to (Hulse, 1983),it is estimated that about 50% of perishable food

commodities including fruits, vegetables, roots and tubers and about 30% of the food grains

including maize, sorghum, millet,rice,cowpeas are lost after harvest in west Africa.

The factors responsible for post harvest food losses in West Africa are

1. Ineffective or inappropriate food processing technology

2. Careless harvesting and inefficient post harvest handling practice

3. Poor transportation media

4. Bad market practice

5. Lack of storage facilities

In essence to reduce post harvest food losses traditional foods have to be improved using

technological food processing techniques. One of these techniques is processing of yam into

instant yam flour.

Yam, Dioscorea (spp), a dicotyledonous perennial plant, is an important source of

carbohydrate for many people of the sub-Saharan region especially in the yam zones of West

Africa. Several species of yam are grown in the in the tropics and temperate zones of the world

since it grows easily, it has large yield and is little affected by disease and pests. It is the second

most important root/tuber crop in West Africa after cassava, with production reaching just under

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one third the level of cassava (FAO, 2008). Some are grown for medicinal purposes and other for

edible purposes. The most common of the edible species are Dioscorea alata L; (known as the

greater yam), Dioscorea cayenensis lam; (the yellow yam) Dioscorea rotundata poir Dioscorea

esculenta (white yam) (IITA 2008). Yam has an energy content of about 30 billion kcal with a

corresponding protein content of 0.66 million ton (wikipedia 2010)

Yam is a source of carbohydrates in human diet being processed into pounded yam for

human consumption. The tubers of yam cannot be stored much longer after harvest before

decaying, and so processing follows immediately after harvesting. Poundo yam which is also

referred to as instant pounded yam flour (IPYF) is a processed white powdery form of yam

(dehydrated yam flour) which is produced desiccating machine. It is a fast means of making

pounded yam which is done by pouring a measured quantity of the yam flour into boiling water,

which is stirred continuously until the required texture and taste is achieved. Yam processing

leading to size reduction includes peeling, slicing, parboiling, grating, drying, drying and sieving.

(Ihekeronye and Ngoddy, 1985)

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2.0 LITERATURE REVIEW

2.1 DESCRIPTION OF YAM

2.1.1 HISTORICAL BACKGROUND OF YAM

Yams (Dioscorea species) are annual or perennial tuber bearing and climbing plants

(IITA, 2008). The genus Dioscorea has over 600 species but only a few are cultivated for food or

medicine (IITA, 2008). The major edible species of African origin are white guinea yam

(D rotundata poir), yellow guinea yam (D. cayenensis lam), and trifoliate or bitter yam

(D dumetorum kunth) (IITA, 2008). Edible species from Asia include water or greater yam

(D alata L) and lesser yam. (D esculenta) Cush-cush yam (D trifida L) originated from the

Americas (IITA, 2008). White guinea yam and water yam are the most important food yams in

terms of cultivation and utilization. Yam tubers may be eaten with sauce directly after boiling,

roasting or frying in oil. The tubers may also be mashed or pounded into dough after boiling,

processed into flour or cooked into pottage with added protein sauce and oils. In addition to their

food and market values, yams play a major role in social-cultural life for a wide range of small

holder’s households especially in the dominant production zone of West Africa. Consumer

demand for yam is generally very high in this sub-region and yam cultivation is very profitable

despite high production costs. (Wikipedia 2010)

Yam can supply a substantial portion of the manganese and phosphorus requirement of

adults and to a lesser extent the copper and magnesium. The tubers can grow up to 2.5 meters in

length and weigh up to 70kg (150pounds) (wikipedia 2010). The vegetable has a rough skin

which is difficult to peel but which softens after heating. The skin varies in colour from dark

brown to light pink. Nigeria has been adjudged as the top producer of yam with a value of

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26.6million metric ton (wikipedia 2010). The table below shows the output of yam production in

2005.

Table 2.1 YAM OUTPUT 2005 (TOP PRODUCERS AS AT 2005)

S/N COUNTRY PRODUCTION (Million metric ton)

1 Nigeria 26.6

2 Ghana 3.9

3 Australia 3.2

4 Cote d’ Ivoire 3.0

5 Benin 2.3

6 Togo 0.6

7 Colombia 0.3

World total 39.9

SOURCE; (Wikipedia, 2010)

The major cultivated species of yam are as follows;

1. Dioscorea rotundata and D. cayenensis

They are native to Africa. They are the most important cultivated yams. In the past, they were

considered two species but most taxonomists now regard them as the same species. There are

over 200 cultivated varieties between them. They are large plants; the vines can be as long as 10-

12 meters (35 to 40 feet). The tubers most often weigh as much as 25kg (60 pounds). After 7 to

12 months growth, the tubers are harvested. In Africa most are pounded into a paste to make

traditional dish called “pounded yam” (Wikipedia, 2010)

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2. Dioscorea alata

This is also called “water yam”, it was first cultivated in Southeast Asia. Although not grown in

the same quantities as the African yams, it has the largest distribution worldwide compared to

other yam species. It is grown in Asia, the pacific islands, Africa and the west Indies.

(Wikipedia, 2010)

3. Dioscorea opposita

This is often called the “Chinese yam”, it is native to china. The Chinese yam plant is somewhat

smaller than the African, with the vines about 3 meters (10 feet) long. It is tolerant to frost and

can be grown in much cooler conditions than other yams. It is now grown in China, Korea and

Japan. The tubers are harvested after about 6 months of growth. Some are eaten immediately

after harvesting and some are used as ingredients for other dishes, including noodles, and for

traditional medicines. (Wikipedia, 2010)

4. Dioscorea bulbifera

This is called the air potato and it is found in both Africa and Asia, with slight differences

between those found in each place. It is a large vine with a length of 6 meters (20 feet) or more.

It produces tubers; however the bulbils which grow at the base of its leaves are important food

product. They are about the size of potatoes weighing from 0.5 to 2kg (1 to 5 pounds). Some

varieties can be eaten raw while some require soaking or boiling for detoxification before eaten.

It is not grown much commercially since the flavor of other yams is preferred by most people.

However it is popular in home vegetable gardens because it produces a crop after only 4 months

of growth and continue to produce throughout the life of the vine,(as long as two years). Also the

bulbils are easy to harvest and cook. (Wikipedia, 2010)

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5. Dioscorea esculenta

This is called lesser yam which was one of the first yam species cultivated. It is native to

Southeast Asia and is the third most commonly cultivated species there, although it is cultivated

very little in other parts of the world. It vines seldom reach more than 3 meters (10 feet) in length

and the tubers are fairly small in most varieties. The tubers are eaten baked, boiled, or fried much

like potatoes. Because of the small size of the tubers, mechanical cultivation is possible, it easy

to prepare and it has good flavor. (Wikipedia, 2010)

6. Dioscorea trifida

This is called the cush-cush yam and it is native to the Guyana region of South America and is

most important cultivated new world yam. Since they originated in tropical rain forest,

conditions of their growth are less related to seasonal changes than other yams. These yams are

often fertilized with human feaces. Because of their relative ease of cultivation and their good

flavor they are considered to have a great potential for increased production. (Wikipedia, 2010)

7. Dioscorea dumetorum

This is also known as the bitter yam and it is popular as a vegetable in parts of West Africa; one

reason being that their cultivation requires less labor than other yams. The wild forms are very

toxic and are sometimes used to poison animals when they mixed with bait. It is said that they

have also been used for criminal purposes. (Wikipedia, 2010)

2.1.2. NUTRITIONAL VALUE OF YAM

Yams are high in vitamin C, dietary fiber, vitamin B6, potassium and manganese. One cubed

yam contains 15.5% of the daily value for vitamin B6. Vitamin B6 is needed in needed by the

body to breakdown a substance called homocysteine, which can directly damage blood vessels

walls. Individuals who suffer from heart attack despite having normal or even low cholesterol

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Levels are often found to have high levels of homocysteine. Since high homocysteine levels are

significantly associated with increased risk of heart attack and stroke, having a good supply of

vitamin B6 makes a great deal of sense. High intakes of vitamin B6 have also been shown to

reduce the risk of heart disease. (coursey, 1967)

Yam products generally have a lower glycemic index than potato products, which means that

they will provide a more sustained form of energy, and give better protection against obesity and

diabetes. (Wikipedia, 2010)

Yams are very good source of potassium, a mineral that helps to control blood pressure. Since

many people do not eat enough fruits and consume high amount of salt in processing food, there

may be deficiency in potassium. Low intake of potassium-rich foods, especially when coupled

with high intake of sodium, can lead to hypertension. In the dietary approach to stop

hypertension (DASH) study, one group ate fruits and vegetables and low fat dietary food in place

of snacks and sweets. This diet delivers more potassium, magnesium, and calcium. Another

group ate a diet rich in fat and low in fruits and vegetable. After eight weeks the group that ate

the enhanced diet lowered their blood pressure by an average of 5.5 points (systolic) over 3.0

points (diastolic). Dioscorin, a storage protein contained in yam may also be of benefit to certain

individuals with hypertension. Preliminary research suggests that dioscorin can inhibit

angiotensin converting enzymes, which would therefore lead to increased kidney blood flow and

reduced blood pressure. (coursey, 1967)

According to (Oyenuga, 1967) the nutrients produced per acre of yam varieties grown in Nigeria

are tabulated as shown below;

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Variety Protein

(Pounds)

Carbohydrate

(Pounds)

Oil

(Pounds)

Mineral

(Pounds)

Total

digestible

nutrients of

peels only

Total

calories per

1000g

White

yam

335 6973 26 190 974 13161

Yellow

yam

411 6957 13 196 1250 13317

Water

yam

556 6622 44 381 1445 12882

Trifoliate

yam

890 6425 92 179 760 13510

Chinese

yam

586 6820 4 184 420 13322

Table 2.2 NUTRIENTS PRODUCED PER ACRE OF YAM VARIETIES GROWN IN

NIGERIA

SOURCE; (oyenuga, 1967)

According to (coursey, 1967) the nutritional value of 1 kg of yam is analysed in the table

below.

Table 2.3 NUTRITIONAL VALUE OF 1 KG OF YAM

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Constituent Composition

Calories 4186 joule

Protein 20g

Calcium 150mg

Iron 10mg

Vitamin A Traces

Thiamin 1mg

Riboflavin 0.3mg

Nicotinic acid 4mg

Vitamin C 50mg

SOURCE; (coursey, 1967)

2.2 THE PRODUCTION STAGES INVOLVED IN INSTANT POUNDED YAM FLOUR (IPYF) PRODUCTION

The production process of instant pounded yam flour consist of simple operations which can be

mechanized (FIIRO, 2005). The units operation can be shown in the flow chart below;

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Yam selection and weighing

1. YAM SELECTION AND WEIGHING: This involves the selection of suitable varieties

of yam, considering the size and shape of the tubers. The wholesome tubers are then

weighed.

2. WASHING: The selected tubers are washed properly to remove adhering sand. The

essence of the washing is to ensure that the peeling is done effectively.

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Washing

Peeling

Slicing

Parboiling

Drying

Grinding

Sieving and packaging

3. PEELING AND SLICING: The washed tubers are carefully loaded into a yam peeling

and slicing machine for peeling the bark of the yam. The pilled tubers are then

mechanically sliced to desirable thickness in a slicing machine made of stainless steel.

4. PARBOILING: The yam slices are blanched in boiling water (parboiling) for some

minutes, depending on the thickness of the slices

5. DRYING: The parboiled yam slices are dried in a dryer at specified drying temperature

for few hours. The dried yams chips are stored in air tight containers

6. GRINDING: The dried yam chips are grinded directly into flour of uniform particle size

distribution.

7. SIEVING AND PACKAGING: The yam flour is sieved and packed into air tight,

moisture proof packaging materials

3.0 STATEMENT OF PROBLEM

The slow progress in upgrading traditional food processing and preservation techniques in the

country, contributes to food and nutrition insecurity. Simple low cost traditional food processing

techniques are the bedrock of small scale food processing enterprises that are crucial to rural

development, employment opportunity, rural-urban migration and associated social problems.

Regrettably, small scale food industries in the country are hampered by adoption of inefficient

and inappropriate technologies, poor management, inadequate working capital, limited access to

banks and other financial institutions, high interest rates and low profit margins.

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4.0 OBJECTIVES

The objectives of this project are:

1. To reduce high post harvest food losses arising largely from limited food preservation

capacity.

2. To reduce seasonal food shortages and nutritional deficiency arising largely from

ineffective food processing techniques.

3. To upgrade traditional food processing and preservation by reducing the drudgery

associated with the preparation of pounded yam.

4. To develop an integrated process plant that will combine or assemble the machines

required in different stages of producing instant yam flour with minimum human

intervention.

5.0 CONTRIBUTION TO KNOWLEDGE

Yams have not been utilized to any appreciable extent. Very limited quantities are used for starch

production. This is due to poor food preservation and processing techniques. However, Poundo

yam production is beginning to gain attention which will drastically increase the use and

production of yam. The capacity to preserve food is directly related to the level of technological

development and as such this project will solve the problem of limitations encountered in using

suitable machines and equipments that are necessary for industrial and even small scale

production. Nigeria being one of the top producers of yam can utilize this opportunity to export

processed yam for economic growth by employing appropriate processing techniques such as

this project. This project will lead to rural empowerment, because farmers will be encouraged to

produce more tubers of yam since it can easily be processed and preserved for exportation. In

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addition, there will employment opportunity for both skilled and unskilled labors which will give

rise to economic empowerment and increased standard of living.

6.0 METHODOLOGY

In achieving the stated objectives of this project the following methods will be applied:

1. Extensive literature review on the description of yam and its nutritional value.

2. Study of the unit operations involved in the production of instant pounded yam flour

(IPYF).

3. Development of suitable machines and equipments required in each unit operation.

4. Assemblage of the developed machines from each unit operations or stages of production

7.0 CONCLUSION

The critical role that mechanization of traditional food processing techniques plays in national

development cannot be overemphasized in Nigeria, because high-post harvest food losses arise

largely from limited food preservation capacity. In essence small scale food industries that

involve lower capital investment and that rely on traditional food processing technologies are

crucial to rural development in the country. By generating employment opportunity in the rural

areas small scale food industries reduce rural-urban migration and the associated social problem.

They are vital to reducing post harvest food losses and increasing food availability.

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REFERENCES

Bahu, R. E, (1997): Fluidized Bed Driers In:C. GJ. Baker (ed) Industrial Drying of Foods

Blackie Academic and Professional, London, pp 65-89

Barr D J and Baker C G J (1997): Specialized Drying Systems In :C G J Baker (ed) Industrial

Drying of Foods Blackie Academic and Professional, London, pp77-80

Coursey, O. (1967): Yams Tropical Agricultural Series. Macmillan pres limited London

Federal Institute of Industrial Research,Oshodi, Nigeria, FIIRO (2005):Instant Pounded

Yam Flour Production Technology, www.fiiro.org , 25/05/2010

Fellow, P.J (2000): Food Processing Technology ; Woodhead Publishing Ltd Cambridge UK

2nd Edition, 2000

Food and Agricultural Organization, FAO (2008): Roots, Tubers, Plantains and Bananas in

human nutrition- nutritive value, methods of cooking and processing, www.fao.org , 25/05/2010

Http://www.en .wikipedia .org /wiki/yam(vegetable) viewed on 25/05/2010

Hulse J. H (1983): Food Science for the richer, poorer, sick and healthy people. Proceedings

instant food science technology, 16 (1), pg 2-15

Ihekeronye,A. L;Ngoddy,P. O.(1985): Integrated food science and technology for the tropics,

Macmillan publishers limited; London England

International Institute of Tropical Agriculture, IITA (2008): Root and Tuber Systems

www.iita.org , 25/05/2010

Oyenuga V. A. (1967) Agriculture in Nigeria: An Introduction. Ibadan university press, Ibadan.

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