EXTRACTION AND CHARACTERIZATION OF

WATERMELON SEED OIL

By

UGWUANYI DAVID EJIKE

(2006/24248EH)

DEPARTMENT OF CHEMICAL ENGINEERING

FEDERAL UNIVERSITY OF TECHNOLOGY, MINNA

NIGERIA

November, 2011

EXTRACTION AND CHARACTERIZATION OF

WATERMELON SEED OIL

By

UGWUANYI DAVID EJIKE

(2006/2424SEH)

A PROJECT SUBMITTED TO THE

DEPARTMENT OF CHEMICAL ENGINEERING,

FEDERAL UNIVERSITY OF TECHNOLOGY, MINNA

NIGERIA

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IN PARTIAL .FULFILMENT OF THE REQUmEMENT FOR THE AWARD OF . ,

BACHELOR OF ENGINEERING (B. ENG) DEGREE IN CHEMICAL

ENGINEERING

NOVEMBER, 2011

DECLARATION

I declare that the work in the project report (thesis) entitled EXTRACTION AND

CHARACTERIZATION OF WATERMELON SEED OIL has been performed (carried out) by

me under the supervision of Dr. lO. Okafor. No part ofthis project report (thesis) was presented

for another degree or diploma elsewhere at any institution to the best of my knowledge.

UGWUANYI DAVID EJIKE Date·

Name of Student Signature

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CERTIFICATION

This project titled "Extraction and Characterization of Watermelon Seed Oil" by UGWUANYI

DAVID EJIKE meets the regulations governing the award of, the degree of Bachelor of

Engineering (B. ENG.) of the Federal University of Technology, Minna, and it is approved for

its contribution to scientific knowledge and literary presentation.

Dr. 1. O. Okafor Date

Supervisor

Dr. M.O. Edoga Date

Head of Department

~~Ob(2-01 ~ External Examiner Date ..------ .

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ACKNOWLEDGEMENT

All thanks to Almighty God who kept me alive up to this point, empowering me with the much

needed wisdom, understanding and knowledge needed for the completion of the work.

My heartfelt appreCiation goes to Dr. J.O. Okafor who professionally supervised this project

work. I humbly appreciate his fatherly advice, the love and affection towards me. I appreci~te the .c'~" "\ ~

efforts of the hard working Lecturers of the Chemical Engineering Department especially Dr.

M.O. Edoga (HOD), to mention but a few who.P.ave in one way affected my life for the better of

it. I appreciate the effort of Mr. Bulus (W AFT Lab) who took it upon himself to assist me in all

the analysis carried out in this research work.

My profound gratitude goes to my beloved mother Mrs. Ugwuanyi Elizabeth and my wonderful

sisters Ogochukwu and her husband Phat Ojikeya, Nkechi and Ogochukwu Okanyi for their ,

prayers, affection and financial support throughout my years of studies. I am also grateful to my

aunty and her husband Mr and Mrs Ndubuisi Nnadi and Mr and Mrs Stanley for their immense

support and contributions during my study at the University. I am also grateful to the entire

Omeje family Mrs. Augusta, Mr and Mrs Augustine, Rv. Fr. Chibundu, Mrs Pauline, Associate

Prof. Joachim and his wife Mrs Pet, Dr. Jude and his wife Mrs. Chioma, Mr and Mrs luke and

Mr Chinedu for their moral support, prayers and attention when I needed them most.

Finally, this work will not be complete without giving appreciation to my wonderful uncle and

his wife Mr and Mrs.'Iyke Ugwuanyi and my lovely friends Samuel Erasmus, C~risty Onourah,

and my spiritual father Pastor Erasmus Uruawuike (Late).

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ABSTRACT

The research titled extraction and characterization of watermelon seed oil was carried to

investigate the effect that different drying methods, solvents and seed size wQuld have on the-

quality and quantity of oil from watermelon (Citrilus lanatus) seeds. Tbe watermelon seeds were

removed from the pod and washed. The sample was weighed and divided into two equal parts;

one part was subjected to sun drying while the other part was .subjected to oven drying (at a

temperature of 30°C). Drying by sun as expected was gradual as compared to the Qven drying

method which was faster and more rapid. The dried seeds (sun-dried or oven ... dried) were de-

husked, dry-milled into fine crumbs using hand milling machine. The powdered product from the

mill was then subjected to oil extraction using hexane and petroleum ether as solvent. Proximate

and physico-chemical analysis of water melon seeds were carried out. The results showed that

the seeds contained 5.15 ± 0.03 % moisture, 4.90 ± 0.14 % ash, 50.48 ± 0.05 % fat,

32.38 ± 0.02 % protein, 6.10 ± 0.02 % crude fibre and 6.35 :i: 0.12 % nitrogen free extract.

Physico-chemical characteristics showed that the pale yellow oil had a specific gravity of

.0.860 ± 0.003 and a refractive index of l.47l. Saponification value was 184.29 - 187.09

mgKOHlg (for both drying methods). Iodine value was 103.04 - 115.12 mgIodine/g (for both

dryillS methods). Acid value was 10.4 - 12.8 mgKOHfg and free fatty acid was 5.2 - 6.4

mgKOHIg (for both drying methods). The peroxide value was 18.74 meq peroxide/g. The water ,

-mdon seed can thus be considered a good source of protein with high nutritional value. Many of

~ physieochemical -properties of the seed oil studied .compared favourably with" other

_~~ se-ed ~Us such as soyabean, cowpea, groundnut etc. The watermelon seed oil

_ dt~b_1l$ potcentiai for use as domestic and industrial oil.

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TABLE OF CONTENTS

Pages Content

1

Title Page "

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Declaration III

Certification IV

Acknowledgement V

Abstract ','

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. Table of Content Xl

List of Tables xu

List of F!gures . CHAPTER ONE ,

1 , ."i

1.0 INTRODUCTION .~

2 1.1 Aims and Objectives .'

3 " " ,1.2 Scope of the Study

3 1.3 Problem Statement

4 .'i'

1.4Justification of the Study .~ \

CHAPTER TWO . 5

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,2.0 LITERATURE REVIEW

2.1 Watermelon Seed Background 5

6 2.2 Oil j:

6 < ~- ~ ~

2.2. I fany Aeids 6

2.2.2 Tooopherots 7

1.2.3 Oxidative Stability 7

2.2.4 Refining 9

2.2.4.1 Degumming

10 2.2.4.2 Caustic Neutralization

10 2.2.4.3 Bleaching

11 2.2.4.4 Deodorization Process

, 2.3 Nutritional Benefits of Watermelon Seed Oil 12

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Content

2.3.1 Application of Watermelon Seed Oil

2.3.2 Health Benefits of Watermelon

2.4 Leaching

2.4.1 Methods of Extraction

2.4.1.1 Supercritical Fluid Extraction

, 2.4, 1.2 Solvent Extraction

2.4.1.3 Mechanical Pressing Extraction

2.4.2 Factors Influencing the Rate of Extraction

2.4,2.1 Particle Size

2.4.2.2 Solvent

2.4.2.3 Temperature

2.4,2.4 Agitation of Fluid

2.4.3 Choice of Solvent

, 2.4.3.1 Selectivity

2.4.3.2 Recoverability

.2.4.3.3 ~olatility

2.4.3.4 Purity

2.4.3.S Solubility

" A: ~ L T ... "· "-.:t'fu ",.,"4';3.'121 _.-tamma'uht~;r

'.$ Pk:,~~Cllemical Properties of Oil

, ~SJ Ad' V:ttJue (free Fatty Acid)

~.$.~ $~,tmifi~Qn Value

l.$'..' i_~,' V~Ju"

2.5.5 Refractive Index

2,5.6 Specific Gravity

2,5,7 Viscosity

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2.6 Proximate Analysis of Oil Bearing Seeds 22 .~ .' . ,

2.6.1 Moisture Content 22

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2.6.3 Ash Content 23 .r·;'

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2.6.4 Nitrogen Free Extract 24

2.6.5 Crude Protein 24

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2.6.6 Oil Content ,1.,

CHAPTER THREE

3.0 MATERIALS AND METHOD 26

3.1 Sample Preparation Analysis 26

3.1.1 Crushing and Grinding 26

3.1.2 Sieving 26

, 3.1.3 Drying 26

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3.1.4 Materials and Apparatus 27

27 3.1.5 Reagents

3.2 Proximate Analysis ' .. 28

3.2.1 Oil Content 28

. ~, .. 3.2.2 Moisture Content

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3.2.3 Crude Fiber 29

3.2.4 Ash Content '." 30

·3.2.5 Nitrogen Free Extract 31

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3.2.6 Crude Protein 32 ' ].:.

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,3.3 Physico - Chemical Properties of Watermelon Seed Oil 32 :!,

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3.3.1 pH 32 '!

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3.3.2 Refractive Index 32

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3.3.3 Viscosity 32

3.3.4 Specific Gravity 33

3.3.5 Acid Value (Free Fatty Acids) . 33

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Content 34

3.3.6 Saponification Value 34 j .

3.3.7 Peroxide Value 35 "

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3.3.8 Ester Value 3S

3.3.9 Iodine Value ' ('

CHAPTER FOUR 37

4.0 RESULTS AND DISCUSSION 37 ;

4.1 Results ',.

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4.2 Discussion of Results

CHAPTER FIVE 47

5.0 Conclusion and Recommendation _.47

5.1 Conclusion 48

5.2 Recommendation : .

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REFERENCES 57 "

APPENDICES " ~'.

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LISTS OF TABLES

Table

Table 4.1 proximate Composition of Watermelon Seed

Table 4.2 Physico _ Chemical properties of Watermelon Seed Oil (Hexane)

Table 4.3 Physico _ Chemical properties of Watermelon Seed Oil (petroleum ether)

Table A1 Oil extracts'using 0.5 mm sample size (petroleum ether solvent)

Table A2 Oil extracts using 1.0 mm sample size (petroleum ether solvent)

Table A3 Oil extracts using 2.0 mm sample size (petroleum ether solvent)

Table A4 Oil extracts using 0.5 mm sample size (hexane solvent)

Table AS Oil extracts using 1.0 mm sample size (hexane solvent)

Table A6 Oil extracts using 2.0 mm sample size (hexane solvent)

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