ABSTRACT

Extracts of Capsicum annuum were studied for their antimicrobial potency against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Shigella spp and Candida albicans using the disc diffusion technique. Qualitative and quantitative phytochemical screening of the ethanol and aqueous extracts of the plant showed the presence of alkaloids, flavonoids, saponins, tannins, steroids, cyanogens and phenols with alkaloids being the dominant compound with a percentage composition of 0.52%. Both the aqueous and ethanolic extracts of Capsicum annuum showed antimicrobial activity against all the test organisms. In aqueous extract, Capsicum annuum showed good inhibitory activity mainly against Escherichia coli and Shigella  spp with zone of inhibition of 19.67 mm ±1.16b and 14.33 mm ±1.52b respectively. The ethanol extract of the plant performed better against Staphylococcus aureus and Pseudomonas aeruginosa with zone of inhibition of 20.33 mm ± 3.06b and 14.33 mm± 0.58b respectively. Based on this finding, this extract may be an alternative to chemical preservatives and used as natural antimicrobial preservatives to reclaim the shelf-life of food.

TABLE OF CONTENTS

Title page i

Certification ii

Dedication iii

Acknowledgement iv

Table of Contents v

List of Tables viii

List of Figures ix

Abstract x

CHAPTER ONE

Introduction 1

1.1 Background of the Study 1

1.2 Objectives of the Study 4

CHAPTER TWO

Literature Review 5

2.1 Description of Capsicum annum (Chilli Pepper) 5

2.2 The Origin of Chilli Pepper 5

2.3 Varieties of Pepper 5

2.4 Intensity of Pepper 7

2.5 Characteristics of Chilli Pepper 7

2.6 Classification of Chilli Pepper 8

2.7 Uses of Pepper 8

2.7.1 Culinary Uses 8

2.7.2 Medicinal Uses 9

2.7.3 Nutritional Uses 9

2.7.4 Crop Defense Uses 10

CHAPTER THREE

Materials and Methods 11

3.1 Collection of Materials 11

3.2 Preparation of Samples 11

3.3 Media Preparation 11

3.4 Production of Extract 12

3.5 Preliminary Phytochemical Screening 12

3.5.1 Qualitative Analysis of Phytochemicals 13

3.5.1.1 Test For Tannins 13

3.5.1.2 Test For Saponins 13

3.5.1.3 Test For Flavonoids 13

3.5.1.4 Test For Alkaloids 14

3.5.1.5 Test For Steroids 14

3.5.1.6 Test For Phenol 15

3.5.2 Quantitative Determination of the Phytochemicals 15

3.5.2.1 Determination of Alkaloids 15

3.5.2.2 Determination of Flavonoids 16

3.5.2.3 Determination of Tannins 16

3.5.2.4 Determination of Saponin 18

3.5.2.5 Determination of Phenols 19

3.5.2.6 Determination of Cyanogenic Glycoside (HCN) 20

3.6 Antimicrobial Activity Test 21

3.7 Statistical Analysis 22

CHAPTER FOUR

Results 22

4.1 Qualitative Phytochemical Screening of Capsicum annuum 22

4.2 Quantitative Phytochemical Screening of Capsicum annuum 24

4.3 Antimicrobial Activity of Capsicum annuum 26

4.4 Relative Potencies of Capsicum annuum Extract 29

CHAPTER FIVE

Discussion and Conclusion 31

5.1 Discussion 31

5.2 Conclusion 33

References