EFFECT OF POTASH ON MICROBIAL ACTIVITY ON COOKED BROWN BEANS

By

OKOLO FELISTER CHIDIMMA

Presented To

Department of Science Laboratory Technology

This work was on the effect of potash on microbial activity on cooked brown beans.  Two samples: A and B for Beans cooked with potash and without potash respectively were used. Pour plate techniques and Biochemical tests were carried out to isolate and confirmed the presence of Microccus luteus and Entrobacter aerogens in the samples. The average count of bacterial isolate in sample A was 1.7x103 cfu/ml while that of sample B was 5.82x103cfu/ml Due to microbial growth inhibition caused by the presence  of potash in sample A, the bacteria count was found to be less than the bacterial count in sample B. Cluster of spores of fungal growth identified were Fusarium spp, Penicillium melinii and Mucor spp. In sample A, the average count of fungal isolates was 6spores/ml and 2spores/ml  for sample B . Due to microbial growth inhibition caused by the presence of potash in sample B, the fungal count was found to be less than the fungal count in sample A. The result proved that potash is a good food preservative against microbes.   

Title page                                     i
Certification                                    ii
Dedication                                    iii
Acknowledgement                                 iv
Table of Contents                                vi
List of Tables                                    x
Abstract                                         xi
CHAPTER ONE
1.0    Introduction                                 1
1.1    Background of the Study                    1
1.2    Statement of the Problem                    5    
1.3    Objective of the Study                        6
1.4    Significance of the Study                    6
1.5    Limitation of the Study                        7

CHAPTER TWO
2.0    Literature Review                             8
2.1    Nutritional Value of Beans                    8
2.2    Sources of Microbial Contamination of Cooked Beans     12
2.3    Activities of Microbes on Cooked Beans            18
2.4    Health Implications of Microbial Contamination of Beans     23
2.5    Potash and its Chemical Composition             24
2.6    Potash as a Food Preservative                 25

CHAPTER THREE
3.0    Materials and Method                        28
3.1    Materials                                 28
3.2    Collection of Samples                        28
3.3    Sterilization of Materials                        28
3.4    Preparation of Culture Media                    29
3.5    Sample Preparation                         29
3.6    Serial Dilution                             30
3.7    Identification and Characterization of Isolated Organism        31
3.8    Gram Staining                             31
3.9    Isolation of Fungal                             32
3.10     Biochemical Test                            33
3.11    Effect of Potash on Microbial Activity on Cooked Brown Beans        37

CHAPTER FOUR
4.0    Results                                     38

CHAPTER FIVE
5.0    Discussion, Conclusion and Recommendation     44
5.1    Discussion                                 44
5.2    Conclusion                                 47
5.3    Recommendation                             49
    References                                 50
    Appendix                                 52
 

LIST OF TABLES
Table 1:    Morphological characteristic Gram Reaction on Isolates                            38
Table 2:    Biochemical Test on each Isolate               39      
Table 3:    Total plate count of Bacteria Isolated from  Cooked Beans                        40   
Table 4:    Isolation and Identification of Fungi from  cooked Beans with Potash             41
Table 5:    Total plate count of Fungi Isolated from          Cooked Brown Beans                42