ABSTRACT

Study of antioxidants producing microorganisms in fruits. Antioxidants producing microorganisms has compelling evidence that a diet rich in fruit and vegetables can help maintain a healthy lifestyle. Lactic acid bacteria was isolated from fruits (Apple, Banana and Grape). The samples were thoroughly washed, air dried and homogenized and fermented between 24-72 hours. The isolates showed clear zone on modified  de man, Rogosa and  Sharpe (Mrs). Catalase negative and Gram positive bacteria such as  Lactococcus, Pediococcus, Streptococcus, Enterococcus were used. The proteolytic activity of these organisms were 6.67±0.58 (Lactococcus), 8.38 ±1.15 for  (Pediococcus), 10.33±0.58 (Streptococcus). The chelating activities was 17.78±0.29 for  Lactococcus, 12.62 ±0.17 (Pediococcus), 10.02±0.25 (Enterococcus) 17.22± 0.26 (Streptococcus). The scavenging activity was 27.73 ±0.28 for Lactococcus, 31.39 ±0.35 for Pediococcus, 18.81±0.18 for Enterococcus and 21.10±0.41 for (Streptococcus). This study emphasis that the consumption of fruits will be healthful practices as it contains natural antioxidants which will remove free radicals. 

TABLE OF CONTENTS

Title page i

Certification ii

Dedication iii

Acknowledgement iv

Table of Contents v

List of Tables vii

List of Figures

Abstract           viii

CHAPTER ONE -    INTRODUCTION 1

1.1 Introduction 1

1.2 Dietary Antioxidants 2

1.3 Natural Antioxidants and its Benefits 2

CHAPTER TWO   -   LITERATURE  REVIEW 4

2.1 Historical Review 4

2.2 Health Benefits of Natural Antioxidants 4

2.3 Natural antioxidants and its Benefits 5

2.4 Antioxidants and its Effects 6

2.5 Importance of Antioxidant in the Body 7

2.6 Microbiological Overview of the Dairy Products 7

2.7 Lactic Acid Bacteria (LAB) 8

2.8 Antioxidant Foods 9

2.9 LAB in Mycotoxin Detoxification 9

2.10 Animal Products Fermentation-NONO 10

2.11 Other Sources of Fermented Foods with Natural Antioxidant           11

CHAPTER THREE - MATERIALS AND METHODS 12

3.1 Materials 12

3.2 Isolation of Bacteria 12

3.3 Characterization  and  Identification of  LAB 12

3.3.1 Biochemical test 13

3.3.2 Catalase test 13

3.4 Identification of LAB Isolates 13

3.5 Microscopic Characteristics        13-14

3.6 Protein Hydrolysis 14

3.6.1 Preparation of Skim Milk Agar and Cultures 14

3.6.2 Measurements of Protein Hydrolysis 14

3.6.3 Selection of Lactic Acid Bacteria Isolates        14-15

3.7 Preparation of Whey Fraction from Fermented Milk 15

3.8 Determination of Antioxidant Activity 15

3.9 Scavenging of 1,1-diphenyl-2-picrylyhydrazyl (DPPH) Free  Radical 15

3.10 Ferrous Chelating Activity (FCA) 15

CHAPTER FOUR -  RESULTS        17-23

CHAPTER FIVE – DISCUSSION, CONCLUSION AND RECOMMENDATION 24

5.1 Conclusion 25

5.2 Recommendation        25-26

References 

Appendixes 

LIST OF TABLES

Table 1: Morphological and Biochemical  characteristics  of bacterial isolates. 1

LIST OF FIGURES

Figure Title Page

1: Shows the occurance of LAB in fruits for antioxidant production 19

2: Shows the protein hydrolysis 20

3: Shows the scavanging activity 21

4: Shows the Chelating Activities of LAB  isolates 22

5: Showing the Standard Deviation of Lab Isolates  23