ABSTRACT

Fungi are major spoilage agents of cereals and other foodstuffs before and during storage. Studies were conducted to determine the fungal pathogens of stored rice (Oryza sativa), maize (Zea mays), and millet (Pennisetum thyphodes) and the effect of fungal spoilage on the proximate and vitamin composition. Samples of deteriorated rice, maize and millet grains were sourced from Ubani market and investigated for fungal growth at plant pathology laboratory in the department of Plant Science and Biotechnology. Isolation of fungi from the grains was carried out on potato dextrose agar (PDA) and water agar (WA). The grains were surface sterilized onto WA and incubated for 3 days at room temperature (25 ± 20c) on the laboratory bench. Emerging fungal growth were transferred to PDA and subsequently sub cultured to obtain pure cultures. The pure cultures were identified and subjected to pathogenicity test. The results showed that Aspergilus, rhizopus, Penicillium, Mucor and Fusarium were spoilage pathogens of the grains. Proximate and vitamin analyses were carried out on the infected and healthy grains. Results of the proximate analysis showed that carbohydrate, fibre, ash and moisture content are significantly higher (LSD: 0.05) in the healthy samples than the infected samples. The carbohydrate and fibre content of the healthy samples ranged from 80.39 ± 39 to 69.80± 0.08 and 0.97 ± 0.14 to 2.41 ± 0.03 respectively. While that of the infected samples ranged from 79.63 ± 0.09 to 69.55 ± 0.09 and 0.46 ± 0.02 to 1.99 ± 0.14. The infected samples had higher protein values which ranged from 11.79 ± 0.09 to 15.52 ± 0.10. While the healthy samples ranged from 10.82 ± 0.05 to 15.29 ± 0.09. The infected samples had higher protein content because advanced fungal deterioration increases protein content mathematically. Results of the vitamin analysis showed that the healthy samples had very high vitamin C than any other vitamin. The value of vitamin C of the healthy samples ranged from 28.15 ± 0.05 to 0.29 ± 0.01 while that of the infected samples ranged from 3.28 ± 0.10 to 5.16 ± 0.20.    

TABLE OF CONTENTS

Title page i

Declaration ii

Certification iii

Dedication iv

Acknowledgement v

Table of contents vi

List of table’s ix

List of plates x

Abstract xi

CHAPTER ONE

1.0 INTRODUCTION 1

1.1 JUSTIFICATION 3

1.2 AIMS AND OBJECTIVES OF THE STUDY 3

 CHAPTER TWO

LITERATURE REVIEW 4

2.0 GENERAL DESCRIPTION OF RICE, MAIZE AND MILLET 4                                          

2.1 RICE (Oryza sativa Linn) 4

2.2 MAIZE (Zea mays Linn) 6

2.3 MILLET (Pennisetum typhoides Stapf. &Hubbard) 8

2.4 COMPOSITION OF RICE, MAIZE AND MILLET          10                                                        

2.5 HEALTH BENEFITS OF CEREALS 11

2.6 FUNGI AS A PATHOGEN TO RICE, MAIZE AND MILLET 12                                                                  

2.6.1 FACTORS INFLUENCING FUNGAL GROWTH AND DETERIORATION OF RICE, MAIZE AND MILLET           13                                                                                                   

2.7 NUTRITIONAL CHANGES IN DETERIORATED GRAINS           14

2.7.1 CARBOHYDRATES 15

2.7.2 PROTEIN 15

2.7.3 VITAMINS 15

2.8 AESTHETIC CHANGES IN THE GRAINS                                          15

2.9 CONTROL OF FUNGAL DETERIORATION IN RICE, MAIZE         16

AND MILLET

CHAPTER THREE

3.0 MATERIALS AND METHOD 17

3.1 COLLECTION OF FOOD SAMPLES 17    

3.2 PREPARATION OF MEDIUM 17         

3.3 ISOLATION AND IDENTIFICATION OF FUNGI 17

3.4 SUBCULTURING AND PURIFICATION           18

3.5 PATHOGENICITY TEST           18

3.6 CONFIRMATION OF ISOLATES USED FOR                                    19

PATHOGENICITY TEST                                      

3.7 CHARACTERIZATION OF PURIFIED MICRO ORGANISM 19

3.8 PROXIMATE AND VITAMIN COMPOSITION OF RICE, 19

MAIZE AND MILLET

3.9 STATISTICAL ANALYSIS 19

CHAPTER FOUR

4.1 RESULTS 20

CHAPTER FIVE

5.1 DISCUSSION 25

5.2 CONCLUSION 27

5.3 RECOMMENDATION 27

REFERENCES 28

APPENDIX 34