Microbiological Examination Of Bacteria In Tapioca Sold

ABSTRACT.

Tapioca serves as “Ready to eat or fast food”.  It serves as delicacy and as food in ceremonies.  It is also a good source of carbohydrates, Protein and Vitamins.  This research work examined the bacterial flora associated with tapioca. Samples of prepared tapioca were analyzed by homogenizing little portion of each samples collected in normal saline. The stock was used to prepare a serial dilutions for each sample until the fourth tube which gave a final dilution of 10^-4.  Inoculation were done using the ninth and tenth dilutions of each sample into the plates labelled accordingly.  The media used were Nutrient agar and MacConkey agar.  After incubation of 24 hrs at room temperature, the bacterial flora insolated form the samples were; Shigella sp, Bacillus sp, Streptococcus sp, Proteus sp, Enterobacter sp, Citrobacter sp, Lactobacillus sp, Escherichia sp, Pseudomonas sp, Salmonella sp, Staphylococcus sp . Enumeration of total heterotrophic bacteria ranged from 2.13 × 10⁴ to 2.38 × 10⁴ cfu/g with Sample C having the lowest colony count and Sample D having the highest colony count, while the enumeration of coliform bacteria range from 2.31× 10⁴ to 2.66× 10⁴ cfu/g indicating that Sample D has the highest total colony forming unit of and Sample C has the lowest total colony forming unit. The average viable count conducted showed that Staphylococcus sp and Escherichia sp had the highest frequency of occurrence with a percentage of 17.  This may be due to differences in the source of water, air utensils, packaging, the hygienic standard of the sellers and their environment during and after processing.

TABLE OF CONTENTS

CHAPTER ONE:

INTRODUCTION                                                                               1

1.1       Background Information                                                           1

1.2       Aim and Objective of the Study                                               3

1.3       Statement of Problems of the Study                                         3

1.4       Justification of the Study                                                          4

1.5       Limitation of the study                                                              4

CHAPTER TWO:   

LITERATURE REVIEW                                                                  5

2.1       The Sources of Microbial Contamination of Tapioca                5

2.2       Food Poisoning by Microbes                                                     6

2.3       Some Bacteria Implicated in Tapioca                                        7

2.4       Some Causative Organisms of Food

Poisoning and their Symptoms                                                  9

2.5       Prevention of Microbial Food Poisoning                                  11

2.6       Methods of Identification and Isolation of Bacteria                12

CHAPTER THREE:           

METHODOLOGY                                                                             15

3.1       Material/Reagents used for the Study                                                  15

3.1.1    List of Materials                                                                        15

3.1.2    List of Reagents                                                                        15

3.2       Data Collection                                                                         16

3.3       Analytical Technique used for the Study                                 16

3.3.1    Methods of Identification                                                        16

3.3.2    Biochemical Tests of the Isolates                                             22

CHAPTER FOUR: 

RESULTS AND DISCUSSION                                                        25

4.1       Results                                                                                                  30

4.2       Discussion

CHAPTER FIVE:   

CONCLUSION AND RECOMMENDATION                              33

5.1       Conclusion                                                                                33

5.2       Recommendations                                                                    34

LIST OF TABLES

Table 1:

Table 2:

Table 3:           Total percentage of bacterial count for four samples

Table 5:

Table 6:

LIST OF FIGURES

Fig 1:   The serial dilution technique

Fig 2:   The streak plate technique

Fig 3:   Staphylococcus aureus

Fig 4:   Escherichia coli

Fig 5:   Bacillus subtilis

CHAPTER ONE

INTRODUCTION

• BACKGROUND INFORMATION

“Tapioca” (Cassava flakes) is described by Okaka in 1997 as a pregelled, snow white, bland, sliced and cassava product.  In tapioca processing, raw cassava tubers are uprooted from the farm or gotten from the market, the root are cut, tubers are peeled and cut into chunks, the chunks are washed to remove the dirt and soil, the washed chunks are put in a cooking pot and water is added to the cooking pot and cooked, once cooked the water is removed from the pot and allowed to cool. A knife is then used to thinly slice the cassavas. The sliced cassavas are put in a bowl and water is added, that is the fermentation process, the cassava is washed several times to remove the stickiness. Cassava is a rich vegetable that contains lots of carbohydrate and key vitamins and minerals. According to (Ihekeronye and Ngoddy 1985), detoxification of cassava consist the removal of the chemical compound cyanogenic glycoside which consist mainly lotaustralin and linamarin.  It is during processing such as fermentation, peeling, grating and boiling that cassava becomes detoxified.  (Collard and Levis 1987) and Akinerle (1984) attributed, the detoxification of cassava to the action of bacterium called Corynebacterium manihot which breaks down the starch to sugar and ultimately to organic which decreases the P^H and leads to the hydrolysis of loutaustralin and linamarin during which gaseous hydrogen cyanide (HCN) is evolved. Cassava which is revamped into Tapioca increases its shelf life, a variety of cassava, portability and removal of cyanide.  Processing also preserves the food form decomposition and makes it available for future use (Ihekeronye and Ngoddy 1985). Revamping cassava into tapioca makes it easier for transportation and packaging compared to the bulky fresh nature.

The cassava product (tapioca) is of many significances to the society, for instance, it serves as “ready to eat food”, and it can also serve as a delicacy in some ceremonies. “Tapioca” can also serve as a source of income to some individuals in the society.

• AIM AND OBJECTIVE OF THE STUDY

This study is aimed at determining the prevalence of bacteria in the tapioca sold in Yenagoa metropolis.

To determine the level of bacteria that can cause food poisoning after consumption.

• STATEMENT OF PROBLEMS OF THE STUDY

Microorganisms are found everywhere in nature. Some of these are pathogenic in nature and can multiply freely, others exists as transient microorganisms while some exist also as facultative anaerobes. In different shops in Yenagoa for food sellers, prepared tapioca are left open form the time they started selling till the time they finish selling and such extended exposure can allow the growth of microorganisms into the tapioca and when ingested by the consumer can cause food poisoning.  Sometimes, saliva due to excess talking of the seller contaminates the food and when taken in by consumer may cause gastroenteritis.  Therefore the problem lies at the unhygienic practice by the sellers before and while selling the food to the consumers.

• JUSTIFICATION OF THE STUDY

To enlighten the food handlers to appreciate clean environment because most bacteria discovered to be implicated in the food like tapioca is due to unhygienic practice (Olatunji 1984).

To create awareness that there is tendency of bacteria growth on the food that is exposed to air for a longtime and the implication is food poisoning.

• LIMITATION OF THE STUDY

This work is limited to the use of two media like Nutrient agar and MacConkey agar to examine the bacteria implicated in tapioca.  It is also limited to Swali and Opolo market due to insufficient time to go other areas.

Limited samples of tapioca were collected due to lack of fund and time.

CHAPTER FIVE

CONCLUSION AND RECOMMENDATION

• CONCLUSION

“Tapioca” a pregelled, bland, snow white cassava product eaten in various parts of Nigeria as a fast food is a good source of carbohydrates, protein and vitamins. Although the methods of preparation varies from individuals.   Customarily, tapioca is soaked in fresh water, revamped and then sold by local women with very little or no charade to hygiene one would therefore expect some level of infection or contamination with enteropathogenic organisms.

The result showed diverse bacterial groups associated with gastroenteritis –stomach flu. Contamination could result from impure water used in washing the utensils. Contamination can also be caused by saliva by talking excessively.  Sometimes when nylon is used packaging, the seller blow it to open before packaging, since microorganisms are ubiquitous, air blown into the nylon may contain microorganism thereby contaminating the food.

• RECOMMENDATION

Given that some ways of contamination of the food have been cited above, it is therefore recommended that steeping in hot water before revamping should be practiced by sellers as this eliminates some microbes.  Awareness as regards to hygiene should be created, feeble and disheveled people should not be allowed to sell such local food.