ABSTRACT
This study investigated the microbiological quality of hawked ready-to-eat African Salad (Abacha). Standard microbiological methods were employed. The media used for the culture and isolation of microorganisms included Nutrient agar, MacConkey agar and Sabouraud Dextrose Agar (SDA).The result shows that the predominant bacterial isolates from African salad belong to Escherichia coli, Streptococcus spp., Proteus spp., Staphylococcus spp. and Serratiamarcescen. The fungal spp. isolated includes Aspergillus spp., Mucor spp., Rhizopus spp. and Saccharomyces spp. The Total Aerobic Plate Counts (TAPC) ranged from 3.8 x 108 to 8.0 x 1010, Coliform Count ranged from 3.2 x 103 to 1.2 x 106, and fungal count ranged from 2.3 x 103 to 1.0 x 106. Based on the specifications by International Commission for Microbiological Specification for Foods (ICMSF), the level of contaminations was unacceptable and unsatisfactory and could be pose serious health challenge.
TABLE OF
CONTENTS
Preliminary
Pages
Title page
i
Certification page
ii
Dedication
iii
Acknowledgement
iv
Table of contents
v
List of Tables
vii
Abstract
viii
Chapter
one
1
1.0 Introduction
1
1.1 Objectives of the study
5
1.1.1 Main Objective
5
1.1.2 Specific Objectives
5
Chapter
two 7
2.0 Literature Review
7
2.1 Ready-To-Eat Hawked food\street
vended foods
7
2.2 African Salad
9
2.3 Microbial Quality 9
2.4 The Potential of Food-handling
personnel to transmit diseases through food 11
2.4.1 Classification of
food-handling personnel according to the potential risk 11
2.5 Transmission of Pathogens
13
2.5.1 Environmental Hygiene
13
2.5.2 Personal Hygiene
14
2.6 Food and Quality
15
2.6.1 Sources of food contamination
16
2.6.2 Food hygiene knowledge and
practices
18
2.7 An overview of food safety 22
2.7.1 Good Manufacturing Practices
(GMP) and Good Hygienic Practices 22
2.7.2 Microbiological food
safety
24
Chapter
Three
26
3.0 Materials and Method
26
3.1 Sample Collection
26
3.2 Microbiological Analysis of
Samples
26
3.3 Media Preparation 26
3.4 Enumeration and
Characterization of microbial isolates 27
3.4.1 Gram Staining 28
3.4.2 Total Aerobic Plate Counts
(TAPC)
28
3.4.3 Coliform Counts
29
3.4.4 Fungal Counts
30
Chapter
Four
31
4.0 Results
31
Chapter
Five
40
5.0 Discussion, Conclusion, and
Recommendation
40
5.1 Discussion
40
5.2 Conclusion
42
5.3 Recommendations
42
References
44
LIST OF TABLES
Table 1 Total
Aerobic Plate Counts (TAPC) of African Salad 33
Table 2 Coliform
Counts 34
Table
3 Fungal Counts 35
Table
4 Microorganisms isolated from
different sampling sites 36
Table
5 Percentages of Bacteria
isolated and their Gram stain results 37
Table
6 Percentages of Fungi isolated 38
CHAPTER ONE
1.0 INTRODUCTION
African salad popularly called
“Abacha, AbachaNcha, Abacha and Ugba” by Igbo tribe of Nigeria, it is an exotic
delicacy and a special salad recipe native to Nigeria. The name African salad
is thought to have originated from the Igbo’s ideology that salad contains lots
of fresh and raw vegetables and some other ingredients consumed without further
cooking, therefore it is a salad and of African origin. African salad is widely
accessed for its composition of food ingredients known to be rich in protein,
carbohydrate, vitamins, and minerals. It can be eaten on its own or in
combination with other snacks like coconut, palm kernel and groundnut. Though
it can be as filling as any other main course meal, African salad is usually
eaten as an in-between meal (African salad: Abacha and Ugba, 2013) or as a side
dish to the various Nigerian rice recipes (Maky, 2013).
Ready to eat (RTE) foods are foods that can be used for
immediate consumption at the point of sale (Clarence et al., 2009). They
can be obtained from fresh products through selection, washing, peeling,
cutting, and sanitization, rinsing, drying and packaging (De Oliveira et al.,
2011) and can be raw or cooked, hot or chilled. They can be consumed without
further heat treatment. Ready meal markets have been major growth sectors in
recent decades as a result of changes in consumer attitudes (Lehtoet al.,
2011). In particular, consumption of RTE salads has been on the rise (De
Oliveira et al., 2011; Anon., 2012).
African salad is also regarded as a
special delicacy during traditional festivals (AbachaNcha: African salad,
2012). Abacha is processed by harvesting cassava tubers, after which they are
peeled, washed and cooked. These are then shredded into fine thin slices, and
soaked overnight for fermentation so as to thoroughly reduce the starch and
hydrogen cyanide from the cassava. The shredded and fermented cassava is again
thoroughly washed the following day before drying it for 2-3 days (African
salad: Abacha and Ugba, 2013). The preparation of African salad takes great
efforts and the ingredients needed to prepare African salad vary according to
ones taste and availability. The key to making a good African salad is to make
sure that all the ingredients are well incorporated (African salad: Abacha and
Ugba, 2013). It can include ingredients such as Ugba (Pentaclethramacrophylla),
palm oil, potash, onions, nutmeg, crayfish, salt, pepper, maggi, ogiri (Ricinuscommunis),
garden egg, garden egg leaves, Utazi leaves (Gongronemalatifolium),
Okazi (Ukazi) leaves (Gnetumafricana), Ozeza (Uzeza) leaves (Piper
guineense), kpomo (cow skin), meat and stockfish/fish (African cassava
salad-Tapioca, 2006; Miriam and Anthonio, 2011; Nigerian Appetizer- Abacha:
African salad, 2012; Maky, 2013; Osewa, 2013). These ingredients are mixed
thoroughly with the shredded cassava (Abacha). The ingredient added is
dependent on one’s choice, purchasing power and availability. African salad can
be served with fried fish/meat over a cold drink (Palm wine, beer, stout or
wine) (African cassava salad-Tapioca, 2006; Miriam and Anthonio, 2011; Nigerian
Appetizer-Abacha: African salad, 2012; African salad, 2013; Osewa, 2013). There
is paucity of information on the chemical and microbiological compositions of
African salad as consumed. Though several works abound on some of the component
ingredients, the notion that African salad is nutritionally rich is only but
speculative based on its component ingredients.
Food of non-animal origin (FoNAO) is eaten in many forms,
and a preponderant component of almost all meals. Although micro-organisms are
traditionally associated with products of animal origin (Leifertet al.,
2008), FoNAO can potentially be associated with large outbreaks as seen in 2011
associated with verocytotoxin-producing E. coli (VTEC) O104 (EFSA,
2013). Using epidemiological data from 2007 to 2011, EFSA (2013) concluded
that: FoNAO were associated with 10% of the outbreaks, 26% of the cases, 35% of
the hospitalisations and 46% of the deaths, and from 2008 to 2011, there was a
rise in the numbers of reported outbreaks, cases, hospitalisations and deaths
associated with food of non-animal origin.
Minimally processed cut and packaged salads are exposed to
a variety of conditions during harvest, preparation, and distribution and these
conditions can increase the potential for microbial contamination (Sagooet
al., 2003). Food borne illness is a major international health problem with
heavy economic consequences (Duff et al., 2003). The increased
consumption of RTE salads together with the associated risk of disease, to
which consumers may be exposed, is a matter of great concern (Oranusi and
Olofunfemi, 2011).
Indicator organisms are not generally pathogenic and are
commonly used by public health practitioners as markers of poor sanitation and
bacterial contamination from environmental sources like soil or from animal or
human faeces (Anon., 2002). Levels of these organisms often act as an indirect
measure of the potential for dangerous faecal pathogens to be present, of the
food quality and of the potential health risk they pose to consumers (Rosminiet
al., 2004).
In previous studies
conducted in different countries, pathogens isolated from several kinds of
salads included S. aureus, Escherichia coli, Enterobacterspp.,
Klebsiellaspp., Salmonella typhi, Serratiaspp., Providenciaspp.
Pseudomonas aeruginosa, Yersinia enterocolitica, Aeromonashydrophila,
and Shigellasonnei(Poorna and Randhir, 2001; Warren et al., 2007;
Wright et al., 2009; Xanthopouloset al., 2009). In the context of
growing awareness on microbial quality of salads the present study therefore
investigate the microbiological quality of hawked ready-to-eat African Salad.
Food borne diseases are a major global problem causing
considerable morbidity and mortality annually (Hanson et al., 2012).
World Health Organization (WHO) reported that every day more than 5000 children
die globally due to consumption of contaminated food and water. Food borne
illnesses are prevalent in all parts of the world and their toll on human
well-being is enormous which lead to major economic loss (Caroline et al.,
2008). The incidence rate of food borne diseases is also rising up. In
industrialized countries about one-third of the population is suffering from
food borne illnesses each year whereas, in developing world the problem is
worse due to overcrowding, poverty, inadequate sanitary conditions and poor
general hygiene (Fratamicoet al., 2005).
Ready-to-eat foods available in market have gained much
popularity over the years because of the ease and the taste these offer.
Despite of their advantages, the category ready-to-eat is considered as
high-risk foods because they do not necessitate any heating or processing prior
to consumption (Cruickshank, 1990).
The
issue of food hygiene covers a broad area including the selection and handling
of raw foodstuffs, personal hygiene of food vendors and sanitation of place of
cooking, waste management and treatment of leftovers as well as prevention of
contamination. It is an undisputable fact that every food can cause illness if
it is contaminated with harmful microorganisms. It is a fact that there are
always microorganisms in the environment. Food is therefore likely to be
contaminated at every stage of its preparation and serving. This statement
stands true considering the preparation of food for sale in open spaces.
Food
safety has been declared a global concern and an increasing public health
concern by international agencies such as the FAO (Food and Agriculture
Organization) and the WHO (World Health Organization). However, the exact
number of food poisoning and food borne diseases is not known since most
incidences are not reported. It has been estimated that food and waterborne
diarrheal diseases are leading causes of illness and death in less develop countries
killing an approximately 1.8 million people annually (WHO, 2002). Thus, have
the potential of seriously damaging the health status of the population and
simultaneously creating an enormous social burden on the communities and their
health system.
Poor
food hygiene practices by food vendors can have a lot of effects on a
substantial number of people who patronize their services. Talk of the spread
of faecal-oral diseases like Typhoid fever, Cholera among others and the amount
that the government and individuals spend on the treatment of these diseases.
―Food, not water, is the source of most causes of diseases in developing
countries. Most illnesses are due to preventable errors in food selection.
The
risks of illness may be reduced by taking measures to minimize contamination
which may occur during preparation in the kitchen, transporting or during
storage (FAO, 2004). It is against this background that this study examines
microbiological quality of hawked ready-to-eat African Salad.
1.1 Objectives of the Study
1.1.1
Main objective
The
broad objective is to investigate the microbiological quality of hawked
ready-to-eat African Salad
1.1.2
Specific objectives
Specific objectives of the study were
to;
i.
Identify the microorganisms present in hawked ready-to-eat African Salad from different
retail outlets.
ii.
To determine the microbial quality of ready-to-eat African Salad by determining its total
microbial counts, coliform counts and the fungal counts of each sample.
iii.
To identify and discuss the different
routes in which ready to eat African salads are contaminated by microbes.
iv.
To create the needed awareness on the
handling of ready to eat African salads to reduce microbial contamination on
them.
v.
To contribute to the knowledge, especially
in the dimension of Community Health, influence policy decision regarding the
regulation of hawked food, help improve upon the quality of food sold by street
vendors and help streamline food vendors’ activities.
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