ABSTRACT

This study on evaluation of bacteriological contamination of tiger nut sold in Ikot Ekpene Metropolis was carried out using standard and aseptical laboratory procedures. The result of the study revealed the following: The bacterial count showed that sample B had the higher count of 1.8×10⁵ cfu/g while sample A had 1.3×10⁵ cfu/ml; Staphylococcus sp, Klebsiella sp, Enterobacter sp and Proteus sp were isolated; Staphylococcus sp had the highest occurrence of 29.4% followed by Proteus sp (28.1%), followed by Enterobacter sp (21.6%) and Klebsiella had the least occurrence (20.9%). The bacteria count recorded in this study was higher than the WHO standard of <10⁵, which implies that the continual consumption of the tiger nut drink will certainly result in health complications and foodborne diseases. It is recommended that Strict hygienic practices during production, handling and distribution of tigernut drinks, use of sterilized plastic containers, natural antimicrobial preservatives, potable water and proper storage conditions should be enforced by relevant regulatory bodies to maintain the general public health from consuming tigernut drink contaminated with pathogenic microorganisms

TABLE OF CONTENTS

Title Page    –         –         –         –         –         –         –         –         –

Certification –         –         –         –         –         –         –         –         –         i

Dedication   –         –         –         –         –         –         –         –         –         ii

Acknowledgement –         –         –         –         –         –         –         –         iii

Abstract       –         –         –         –         –         –         –         –         –         iv

Table of Content    –         –         –         –         –         –         –         –

CHAPTER ONE: INTRODUCTION

1.1 Background of the Study – –         –         –         –         –         1-3

1.2 Aim and Objectives of the Study –         –         –         –         3-4

1.3 Scope and Limitation of the Study –         –         –         –         4

CHAPTER TWO: LITERATURE REVIEW

2.1     Origin and Geographical Distribution of Tigernut   –         –         5-6

2.2     Cultivation of Tigernut    –         –         –         –         –         –         7-8

2.3     Nutritional Composition of Tigernut Tuber   –         –         –         8-12

2.4     Health Benefit to Tigernut         –         –         –         –         –         12-16

2.5     Factor Enhancing Microbial Foodborne Outbreak   –         –         16-18

2.6     Microbial Contaminant in Foods         –         –         –         –         19

2.6.1  Lactic Acid Bacteria         –         –         –         –         –         –         19-20

2.6.2  Total and Fecal Coliforms          –         –         –         –         –         20-21

2.6.3  Escherichia coli     –         –         –         –         –         –         –         21-22

2.6.4  Staphylococcus aureus    –         –         –         –         –         –         22-23

2.6.5  Listeria monocytogenes   –         –         –         –         –         –         23-24

2.7     Intervention Strategies Against Microbial

Foodborne Outbreak        –         –         –         –         –         –         25-26

CHAPTER THREE: MATERIALS AND METHOD

3.1     Materials and Reagents    –         –         –         –         –         –         27

3.2     Method        –         –         –         –         –         –         –         –         27

3.2.1  Sample Collection  –         –         –         –         –         –         –         27

3.2.2  Serial Dilution       –         –         –         –         –         –         –         28

3.2.3  Sterilization of Glasswares and Media –         –         –         –         28

3.3     Bacteriological Analysis  –         –         –         –         –         –         28

3.3.1  Cultivation of Microorganism    –         –         –         –         –         28-29

3.3.2  Enumeration of Bacterial Isolates        –         –         –         –         29

3.3.2  Purification of Bacterial Isolates          –         –         –         –         29

3.3.4  Characterization and Identification of Bacterial Isolates    –         30

CHAPTER FOUR: RESULTS AND DISCUSSION

4.1     Results         –         –         –         –         –         –         –         –         31-34

4.2     Discussion   –         –         –         –         –         –         –         –         35-39

CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS

5.1     Conclusion  –         –         –         –         –         –         –         –         40

5.2     Recommendations –         –         –         –         –         –         –         40-41

References

                                                CHAPTER ONE

1.0                                        INTRODUCTION

1.1     Background of the Study

Tiger nut (Cyperus esculentus L.) grows freely as a tuber and is largely eaten in Nigeria and in various parts of West and East Africa. It is one of the best nutritional crops used to supplement diets with its high iron and calcium contents for growth and deve1opmcnt of the body (Sanchez-Zapata et al., 2014) and FAO (2015) reported that tiger nut tubers are rich in starch (20.30% of DW) and fat (20-28% DW) with small protein content which is about twice the quantity in cassava. Chandrasekara and Joseph (2016) states that tiger nuts could serve as an alternative to cassava in the baking industry due to the nutritional and therapeutic composition.

Non-alcoholic tigernut drink is rich in nutrients which encourages growth of microorganisms. It has a short shelf life which could be attributed to poor hygienic practices during preparation, packaging, storage and distribution which predisposes the product to microbial contamination (Musa and Hamza, 2013). Studies have shown that non-alcoholic drinks prepared at home using traditional methods or commercially by industries are predisposed to microbial contamination (Okereke, 2015). According to a study carried out by Umaru (2014) no sample of commercially prepared tigernut beverage contained viable microorganisms but Escherichia coli, Bacillus spp., Shigella sp. yeasts and moulds were isolated from home-made tigernut beverage. Egbebi and Seidu (2011) reported the presence of Escherichia coli, Staphylococcus aureus and Salmonella sp. from tigernut beverage (kunu aya) sold in the University of Jos community, Plateau state, Nigeria.

According to Ayeh (2014), the various microbial contaminants can be contracted before, during or after harvest. Some of the different microbial species identified with tiger nuts include Aspergillus flavus, Aspergilius niger Sacchromyces cerevisiae., Saccharomyes fubiligera Fuscirium solani, Candida pseudotropicalis Bacillus subtilis, and Staphylococcus aureus. The various microorganisms that find their way into foods are either introduced from the soil were they are grown, or during harvest, packaging, storage and handling (Nyarko et al., 2011). The occurrence of microorganism in high numbers in the tiger nut drinks could be traced to poor personal hygiene, handling, storage, vending and dispensing conditions by the hawkers. Also, the use of bare hands, rusted cups, contaminated water during washing and regular sprinkling to wet the nuts surfaces for freshness could be responsible for the microbial contamination.

The growing interest and increase in the production and consumption of tiger nut drink in Nigeria has made it a great concern to examine its microbial quality. It has therefore become necessary to ensure the safety of tiger nut drink because of the health of its numerous consumers.

1.2     Aim and Objectives of the Study

The aim of this study is to evaluate the bacteriological contamination of tiger nut sold in Ikot Ekpene Metropolis.

The objectives of this study are

1. To determine the bacterial contamination of tiger nut drink
2. To determine the fungal contamination of tiger nut drink
3. To compare the result of this study with previous studies
4. To make useful recommendation base on the result of this study

1.3     Scope and Limitation of the Study

This study focus on the bacteriological analysis of tiger nut drink sold in Ikot Ekpene Metropolis. This is due to time and financial constraints.