EVALUATION OF ANTIOXIDANT POTENTIAL OF MONODORA

MYRISTICA (AFRICAN NUTMEG)

BY

IBOLO MARTHA NNEKA

BC/2006/076

DEPARTMENT OF BIOCHEMISTRY

FACULTY OF NATURAL SCIENCES

CARITAS UNIVERSITY,

AMORJI-NIKE, ENUGU STATE.

AUGUST, 2010

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TITLE PAGE

EVALUATION OF ANTIOXIDANT POTENTIAL OF MONODORA

MYRISTICA (AFRICAN NUTMEG)

BY

IBOLO MARTHA NNEKA

BC/2006/076

A PROJECT SUBMITTED TO THE DEPARTMENT OF

BIOCHEMISTRY

IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE

AWARD OF BACHELOR OF SCIENCE (B.Sc.) DEGREE

IN BIOCHEMISTRY

AUGUST, 2010.

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APPROVAL PAGE

We hereby certify that the research work in this report is solely the work of IBOLO

MARTHA NNEKA with Registration Number BC/2006/076 for the award of Bachelor of

Science Degree (B.Sc.) in the Department of Biochemistry, Caritas University Amorji-

Nike, Enugu state.

…………………………... ……………………………

Dr. Charles N. Ishiwu Date

(Supervisor)

………………………….. ……………………………

Mr. Moses Ezenwali

(Head of Department) Date

…………………………… ……………………………

External Examiner Date

August, 2010

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DEDICATION

This work is dedicated to Almighty God for His faithfulness to me and for seeing me

through, in this citadel of learning.

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ACKNOWLEDGEMENT

I give joyful thanks and praise to Almighty God who in spite of all odds, made this project

research a reality. He has always been faithful to me. My special appreciation goes to my

supervisor, Dr. Charles N. Ishiwu for his warmly guidance and supervision. His unreserved

kindness and understanding not only inspired me but also encouraged me throughout the

trying moments of this work. I also wish to express my indebtedness to my Honourable

HOD, Mr. Moses O.Ezenwali for his unrelentful assistance throughout my laboratory work

and who contributed in no small measure to the completion of this work.My sincere

gratitude goes to my most learned and zealous lecturers, Mrs. Oluchi Ajemba, Mr. Eze-

steven Peter, Dr. Ikpe, Mr. P. Ugwudike, and Mr. Omeh Yusuf.

My most profound gratitude goes to my loving and caring parents, Sir and Lady P. O. Ibolo

for their moral and financial support, whose love for education brought me to this citadel of

learning. My special thanks also goes to the managing director, Aniuzo international

limited (Palm Kernel Oil Mills Division), Emene, who source partly for the raw material

used for this research. My thanks also goes to my caring chancellor Rev. Sr. Kate Ikenga

for her advice and support to me. I thank my siblings: Blessing, Elizabeth, Anthony and

Christopher, who have been an everlasting source of love, strength and encouragement. I

wouldn’t forget to appreciate my colleagues, friends who have contributed inestimably

throughout the course of this work. In this respect, I am grateful to Patricia, Chidera, Kofi,

Chijioke, Tony, Chizoba, Peace, Modesta, and a host of others.

IBOLO MARTHA NNEKA

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ABSTRACT

This work evaluates the antioxidant potential of Monodora myristica (African nutmeg).

Monodora myristica extract was obtained by solvent extraction using n-hexane and used as

treatment on freshly prepared crude palm kernel oil and palm oil. Equal volume of oil

samples were subjected to different concentration of extract treatment (0.2ml,0.4ml, 0.6ml,

0.8ml, 1.0ml using syringe. These oil samples were equally divided into two groups SS and

SR. Group SS was stored under the sun and group SR was stored in the room for three

weeks. These treated oil samples were analyzed on weekly basis at two different

parameters: Acid value (AV) of free fatty acid and thiobarbituric acid (TBA) value, using

standard methods. The main effect of extract was determined using ANOVA. For the two

varieties of oil, the acid value of free fatty acid increased significantly (P<0.05) as the

period extends for group SS without extract while those for group SR showed no

significant increase. But AV of oil samples treated with higher extract concentration

decreased significantly (P<0.05) for both groups SS and SR. TBA value also showed the

same trend of AV. Hence, monodora myristica extract yielded reducing effect in the

oxidative level of the oil varieties.

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TABLE OF CONTENTS

Title page ---------------------------------------------------------- i

Approval page --------------------------------------------------------- ii

Dedication --------------------------------------------------------- iii

Acknowledgement --------------------------------------------------------- iv

Abstract --------------------------------------------------------- v

Table of content --------------------------------------------------------- vi-viii

List of tables -------------------------------------------------------- xi

List of figure -------------------------------------------------------- x

Abbreviation -------------------------------------------------------- xi

CHAPTER ONE

1.0 Introduction --------------------------------------------------------- 1

1.1 Significance of study ----------------------------------------------- 6

CHAPTER TWO

2.0 Literature Review ------------------------------------------------ 7

2.1 African nutmeg (Monodora myristica) ---------------------------- 7

2.1.1 Scientific classification ------------------------------------------ 7

2.1.2 Habitat/ ecology of Mondora myristica ---------------------------- 8

2.1.3 Characteristics/morphology of monodora myristica ------------- 8

2.2 Oil Palm --------------------------------------------------- 9

2.2.1 Scientific classification ----------------------------------------------- 10

2.2.2 Origin and description of palm oil --------------------------------- 10

2.2.3 The Chemical composition of palm oil -------------------------- 11

2.2.4 Physical characteristics of palm oil products ------------------ 14

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2.3 Palm kernel oil ------------------------------------------------------ 14

2.3.1 The chemical composition of palm kernel oil------------------- 15

2.4 Modern uses of palm oil and palm kernel oil------------------- 16

2.5 Lipid oxidation----------------------------------------------------- 16

2.5.1 Lipid oxidation pathway ------------------------------------------ 21

2.5.2 Mechanism of oxidation ------------------------------------------ 22

2.6 General antioxidant action --------------------------------------- 24

2.6.1 Mechanism of antioxidant action ------------------------------ 24

2.6.2 Antioxidant molecules -------------------------------------------- 26

2.7 General review of photochemistry of monodra myristica -- 27

2.7.1 Alkaloids ---------------------------------------------------------- 27

2.7.2 Flavonoids -------------------------------------------------------- 27

2.7.3 Glycosids -------------------------------------------------------- 28

2.7.4 Saponins ---------------------------------------------------------- 28

2.7.5 Tannins ------------------------------------------------------------ 29

2.8 Application of vegetable oils ----------------------------------- 29

2.8.1 Factors that cause oxidative rancidity in vegetable oil ------ 30

2.9 Nutritional signification ----------------------------------------- 33

CHAPTER THREE

3.0 Materials and methods -------------------------------------------- 34

3.1 Equipment/apparatus ---------------------------------------------- 35

3.2 procedurement of raw materials --------------------------------- 35

3.3 Study design --------------------------------------------------------- 37

3.4 Sample preparation ------------------------------------------------ 37

3.5 Chemical analysis ------------------------------------------------- 38

3.5.1 Determination of acid value (Av) ------------------------------- 38

3.5.2 Determination of thiobarbituric acid number.------------------ 38

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3.6 Statistical analysis ------------------------------------------------ 39

CHAPTER FOUR

4.0 Result and Discussion ------------------------------------------- 40

4.1 Changes in Acid value of Palm Kernel and palm oil -------- 46

4.2 Changes thiobarbituric acid value of palm kernel and palm oil--- 46

4.3 Effect of monodora myristica extract on the

chemical indices of oil on storage -------------------------------- 47

CHAPTER FIVE

5.0 Summary and conclusion -------------------------------------------- 48

5.1 limitations--------------------------------------------------------------- 51

5.3 Future recommendation ---------------------------------------------- 51

References ------------------------------------------------------------------------- 53

Appendix I -------------------------------------------------------------------------- 62

Appendix II ------------------------------------------------------------------------- 63

Appenedix III ---------------------------------------------------------------------- 65

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LIST OFF TABLES

Table 1: Fatty acid composition of palm oil (palm oil)

Table 2: Fatty acid profile of palm kernel oil (palm kernel )

Table 3: Acid value for palm kernel oil

Table 4: Acid value for palm oil

Table 5: Thiobarbituric acid value for palm kernel oil

Table 6: Thiobarbituric acid value for palm oil

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