MICROBIOLOGICAL ANALYSIS OF ZOBO DRINK PRESERVED WITH SCENT LEAVES

ASTRACT

The microbiological quality of zobo drink preserved with scent leaves was evaluated. A total of five (5) apparently zobo drinks preserved with scent leaves were purchased from five different locations. They were evaluated using standard microbiological technique and the zobo drinks preserved with scent leaves sample were in three ratios (95% zobo: 5% scent leaves (ZSA), 90% zobo + 10% scent leaves (ZSB), 85% zobo + 15% scent leaves (ZSC) respectively. Twenty three (23) bacteria species and fourteen (14) fungi species were identified from zobo drink preserved with scent leaves samples. This reveals the major bacterial species to be Enterobacter spp, Staphylococcus aureus, Bacillus spp, and Micrococcus spp., and fungi species to be Aspergillus niger, Rhizopus spp and Penicillium spp. The bacterial and fungal counts decreased as the days increased with day 1 having the highest bacterial and fungal counts at 1.41x105 (cfu/ml) and 3.1x104 (cfu/ml) respectively. The control samples were generally higher than the counts recorded on the bacterial and fungal counts. Zobo + scent leaves (ZSC) recorded the highest bacterial count at 1.41x105 (cfu/ml), while the least was recorded for (ZSA) at 1.01x106 (cfu/ml). Zobo + Scent (ZSC) recorded the highest fungal counts at 3.1x104 (cfu/ml), while the least was recorded for ZSA at 1.2x105 (cfu/ml). From this study, Bacillus spp and Staphylococcus aureus were the most frequently occurring isolates with a high percentage occurrence of 8(21.6%) and 6(16.2%), while Penicillium spp was the most frequently occurring isolate. Occurrences of these microorganisms are largely due to their presence in nature. Their association with foods such as the commercial zobo drinks may be as a result of poor hygiene or poor sanitary condition. The microbial counts showed that among the zobo drink preserved with scent leaves samples, zobo + scent leaves (ZSC) is the most predisposed product to microbial population due to the high microbial counts recorded.

TABLE OF CONTENTS

Title page                                                                                                                                i

Certification                                                                                                                           iii

Dedication                                                                                                                              iv

Acknowledgement                                                                                                                  v

Table of contents                                                                                                                    vi

Lists of Table                                                                                                                          viii

Abstract                                                                                                                                  ix

CHAPTER ONE

1.0       Introduction                                                                                                                1

1.1       Aim of Study                                                                                                              4

1.2       Objectives Include                                                                                                      4

CHAPTER TWO

2.0       Literature Review                                                                                                       5

2.1       Traditional Beverages                                                                                                5

2.2       Safety and Quality Issues Associated with Traditional Beverages (TBs)               5

2.3       Zobo Drink                                                                                                                 6

2.3.1    Uses of Zobo Drink                                                                                                    6

2.2.1    Preparation of Zobo Drink                                                                                         7

2.2.2    Safety and Quality Issues Associated with ‘Zobo Drink’ (ZD)                               7

2.3       Quality of Zobo Drink Prepared and Consumed in Nigeria                                       8

2.3.1    Microbial Assessment                                                                                                9

2.4       Physicochemical and Proximate Composition of Zobo Drink                                    11

2.5       Potential Health Effects of Zobo Drink in Nigeria                                                    12

2.5.1    Microorganisms Associated-Health Effects                                                               12

2.5.2    Phytonutrients and Proximate Composition Health Effects                                       13

2.6       Scent Leaf                                                                                                                   15

2.7       Fortification/Preservation of Zobo with Scent Leaves                                               15

2.8       Other Spices Used for the Preservation/Fortification of Zobo                                    16

2.8.1    Lime                                                                                                                            16

2.8.2    Cinnamon (Cinnamomum zeylanicum L)                                                                   17

2.8.3    Clove                                                                                                                          18

CHAPTER THREE

3.0       Materials and Methods                                                                                               20

3.1       Sample Collection and Preparation                                                                            20

3.3.2    Sterilization Method                                                                                                   20

3.2       Preparation of Extracts                                                                                               20

3.2.1    Preparation of zobo with scent leaves                                                                        21

3.3       Microbial Analysis                                                                                                     21

3.3.1    Media Used                                                                                                                 21

3.4       Isolation of Microorganisms                                                                                      21

3.4.1    Sample Inoculation                                                                                                     21

3.5       Identification of Bacterial and Fungal Isolates                                                          21

3.5.1    Gram Staining Techniques                                                                                         22

3.6       Biochemical Test                                                                                                        22

3.6.1    Oxidase Test                                                                                                               22

3.6.2    Catalase Test                                                                                                               23

3.6.3    Motility Test                                                                                                               23

3.6.4    Indole Test                                                                                                                  23

3.6.5    Citrate Utilization Test                                                                                               24

3.6.6    Coagulase Test                                                                                                           24

3.6.7    Urease Test                                                                                                                 24

3.7       Identification of Fungal Isolates                                                                                 25

3.7.1    Wet Preparation                                                                                                          25

3.7.2    Colonial Morphology                                                                                                 25

3.8       Determination of Percentage Occurrence of Isolates from the Zobo Drinks

            Samples                                                                                                                      25

CHAPTER FOUR

4.0       Results                                                                                                                        26

CHAPTER FIVE

5.0       Discussion, Conclusion and Recommendations                                                        36

5.1       Discussion                                                                                                                   36

5.2       Conclusion                                                                                                                  42

5.3       Recommendations                                                                                                      42

            References

LIST OF TABLES

CHAPTER ONE

1.0       INTRODUCTION

Zobo drinks are traditional non- alcoholic beverage which is consumed in most part of Nigeria, mostly in northern part of Nigeria (Osuntogun, 2004). The economic and religious situation in Nigeria has made the zobo drink gain wide acceptance in different occasions. It’s used as refreshment, entertainment in parties or as appetizers before the main dish is served and it is also sold in market to various consumers. The zobo drink is a red liquid drink and taste like fruit punch, served as a fair source of vitamin A, riboflavin, niacin, calcium and iron, and is low in sugar content (Qi et al 2005).

This drink also contains anthocyanins and Vitamins C, among others and it is used in curing minor stomach ailments, sore throat and strengthening the heart among other uses (Olawale, 2011). Zobo drink is extracted from the dried reddish purple calyces of the plant Hibiscus sabdriffa. The calyces are used to produce herbal teas and other food products. The juice drink which is usually obtained by extraction of the calyx of Hibiscus contains about 1% solid. The drink contains some microorganisms which can cause food spoilage (Omemu et al., 2006). At present, the production processes in neither mechanized nor standardized.

Furthermore, the mode of packaging or dispensing of the juice in nylon or plastic container before retailing, that is taken as Zobo i.e the largely unregulated nature of the trade, and poor hygienic practices as well as lack of running water, toilet, proper storage and waste disposal facilities at preparation and services point has resulted in poor sanitary conditions exposure to potential contaminants and an increased risk to public health (Omemu and Aderoju, 2008). Consequently, street drinks and foods safety has remained a major public health concern globally, and more importantly in Nigeria were the regulation of this critical sector is virtually non-existent or inadequate, making street foods and drinks hazardous source of nutrition (Wada-kura et al., 2009).

Foods frequently serve as vehicle for spreading of several organisms some of which are pathogenic (Singleton, 2009). Many picnic suppers and banquets have come to a disastrous end which home prepared foods and drinks serves not only as food and drinks for guest, but also as the vehicle for transmitting staphylococcus food poisoning.

Zobo is found to be rich in vitamins, natural carbohydrates, protein, calcium, iron, other antioxidants and minerals (Babalola et al., 2000). The leaves of the plant are used as vegetables and the seeds as source of oil (Okoro, 2003). Hibiscus, especially roselle is used in folk medicine as a diuretic mild laxative treatment for cardiac and nerve diseases and cancer. Roselle is associated with traditional medicines and is used as treatment for several diseases such as hypertension and urinary tract infection. The green leaves are used as spicy version of spinach (Kuriyan et al., 2010). The seeds are said to be diuretic and tonic in action and the brownish-yellow seed oil is claimed to heal sores on camels. A review by Lin et al., (2011) stated that specific extract of Hibiscus sabdariffa exhibits activities against atheroscierosis, liver disease, cancer, diabetes and other metabolic syndromes.

Zobo is becoming acceptable in social gathering because it is economically affordable and attractive to many people more than soda (Olayemi et al., 2011). Increase in religious and health campaigns against alcoholic beverages in Nigeria and the consequent decrease in the consumption of alcoholic beverages in certain areas has afforded Zobo drink great potential as a local alternative to imported red wines in particular and alcoholic beverages in general (Egbere et al., 2007). Recently, zobo drink has become a main source of income in many homes both in rural communities and more in the urban areas where cottage business has increased due to support from the government through the poverty alleviation schemes, thereby alleviating poverty among the people (Essien et al., 2011).

The greatest limitation for large-scale production of zobo drink is the rapid deterioration of the drink. Its shelf-life is approximately twenty-four hours following production, if not refrigerated. The drink contains some microorganisms which can cause food spoilage (Omemu et al., 2000). Furthermore, the mode of packaging the juice in nylon or plastic containers before retailing, and the poor hygienic practices as well as lack of portable water, toilets, proper storage and waste disposal facilities at preparation and service points have resulted in poor unsanitary conditions and thus served as potential contaminants and increased risk to public health (Omemu and Aderoju, 2008). The microorganisms associated with the deterioration of zobo include E. coli, Bacillus spp, S. aureus, S. faecalis, Proteus spp, Enterobacter spp, Klebsiella spp, Micrococcus spp Aspergillus spp, Penicillium citrinum, Fusarium oxysporum, Rhizopus spp and Mucor spp (Raimi, 2013).

Ocimum gratissimum is popularly known as scent leaf. It is a full developed flowering plant with root, stem and leaves systems. The plant is naturally used in the treatment of different diseases like diarrhea, headache, fever, ophthalmic, skin disease and pneumonia (Ilori et al., 2006). In many parts of the world, especially Africa and Asia, plant parts are used for the treatment of various ailments such as inflammation, fever, gout (Krawinkel). The leaves of Ocimum gratissimum is used for prevention and treatment of gout, catarrh, fever and malaria which has been found to be associated with free radical generation (Pamplona-Roger, 2004). Scent leave is a major spice used in the production of Zobo drink. Typically, scent leave reduces the microbial density of the zobo drink (Braide et al., 2012; Adesokan et al., 2013). Like moringa, scent leave reduced the population of M. lutens, M. roseus, S. aureus, B. subtilis, Enterobacter faecalis, R. stoloifer, A. flavus, F. poae and P. caseicolum, but do not have effect on the population of S. cerevisiae, S. ellipsoideus (Braide et al., 2012). Typically, the ability of scent leave to have effects on the microbial quality of zobo could be due to the presence of secondary metabolites found in them. Also blended scent leave and moringa has superior effect on the bacterial density of zobo as when compared to separate blends (Adesokan et al., 2013).

1.1       AIM OF STUDY

The aim of this study is to evaluate the microbiological quality of zobo drink preserved with scent leaves.

1.2       OBJECTIVES INCLUDE:

·       To isolate and identify various bacteria and fungi species present in zobo drink and zobo drink preserved with scent leaves.

·       To determine the microbial counts of retailed zobo drink and zobo drink preserved with scent leaves

·       To determine the percentage occurrence of the various isolates from the zobo drink and zobo drink preserved with scent leaves

Buyers has the right to create dispute within seven (7) days of purchase for 100% refund request when you experience issue with the file received. 

Dispute can only be created when you receive a corrupt file, a wrong file or irregularities in the table of contents and content of the file you received. 

ProjectShelve.com shall either provide the appropriate file within 48hrs or send refund excluding your bank transaction charges. Term and Conditions are applied.

Buyers are expected to confirm that the material you are paying for is available on our website ProjectShelve.com and you have selected the right material, you have also gone through the preliminary pages and it interests you before payment. DO NOT MAKE BANK PAYMENT IF YOUR TOPIC IS NOT ON THE WEBSITE.

In case of payment for a material not available on ProjectShelve.com, the management of ProjectShelve.com has the right to keep your money until you send a topic that is available on our website within 48 hours.

You cannot change topic after receiving material of the topic you ordered and paid for.