TABLE OF CONTENTS
DECLARATION………………………………………………………………………………………………. i
DEDICATION…………………………………………………………………………………………………. ii
ACKNOWLEDGMENT…………………………………………………………………………………… iii
TABLE OF CONTENTS………………………………………………………………………………….. iv
LIST OF TABLES…………………………………………………………………………………………… vi
LIST OF FIGURES………………………………………………………………………………………… vii
ABBREVIATIONS AND ACRONYMS…………………………………………………………… viii
OPERATIONAL DEFINITIONS……………………………………………………………………… ix
ABSTRACT……………………………………………………………………………………………………. xi
CHAPTER ONE: INTRODUCTION………………………………………………………………… 1
CHAPTER TWO: LITERATURE REVIEW………………………………………………………. 8
CHAPTER THREE: MATERIALS AND METHODS………………………………………… 20
CHAPTER FOUR: RESULTS…………………………………………………………………………. 29
CHAPTER FIVE: DISCUSSION, CONCLUSIONS AND RECOMMENDATIONS 47
References……………………………………………………………………………………………………… 58
Appendices…………………………………………………………………………………………………….. 61
Appendix 1 : Informed Consent………………………………………………………………………… 61
Appendix 2: Observation Checklist……………………………………………………………………. 64
Appendix 3: Questionnaire………………………………………………………………………………… 66
Appendix 4: KU Ethics Review Committee Approval……………………………………………. 68
Appendix 5: NACOSTI Research Authorization…………………………………………………… 69
Appendix 6: NACOSTI Research Clearance Permit………………………………………………. 70
LIST OF TABLES
Table 2. 1: General microbiological profile of harvested fruits and vegetables……….. 17
Table 3. 1: Response rate of vendors and selection of fruit samples……………………… 22
Table 4. 1: Socio-demographic characteristics of fruit vendors…………………………….. 30
Table 4. 2: Food hygiene knowledge of vendors………………………………………………… 31
Table 4. 3: Food hygiene knowledge score by clusters………………………………………… 32
Table 4. 4: Food hygiene practices……………………………………………………………………. 34
Table 4. 5: Food hygiene practice score by clusters…………………………………………….. 35
Table 4. 6: General profile of street fruit vending place………………………………………. 37
Table 4. 7: Hygiene of the vending environment………………………………………………… 38
Table 4. 8: Hygiene condition score by clusters………………………………………………….. 39
Table 4. 9: Bacterial load (mean log10 CFU/g +/-SD) of specific fruits by cluster….. 41
Table 4. 10: Coliform load (mean log10 CFU/g +/-SD) of specific fruits by cluster… 41
Table 4. 11: Mould and Yeast load (mean log10 CFU/g +/-SD) of specific fruits by cluster 42
Table 4. 12: Relationship between socio-demographic factors and hygiene status….. 43
LIST OF FIGURES
Figure 1. 1: Factors that affect hygiene and safety of foods in public places…………… 7
Figure 3. 1: Nairobi Central Ward-Starehe constituency……………………………………… 21
Figure 4. 1: Food hygiene knowledge level scores……………………………………………… 32
Figure 4. 3: Food hygiene practice score…………………………………………………………… 35
Figure 4. 4: Hygiene condition scores……………………………………………………………….. 38
Figure 4. 5: Hygiene status scores by clusters…………………………………………………….. 40
Figure 4. 6: Relationship between hygiene knowledge and hygiene status…………….. 44
Figure 4. 7: Relationship between hygiene practice and hygiene knowledge…………. 45
ABBREVIATIONS AND ACRONYMS
ACC/TPC – Aerobic colony count/Total plate count
CBD – Central Business District
CDC – Centre for Disease Control and prevention
EU – European Commission
GAP – Good agricultural practices
GMP – Good manufacturing practices
IEC – Information education communication
KEBS – Kenya Bureau of Standards
MOH – Ministry of Health
NCC – Nairobi City Council
NSSF – National Social Security Fund
NACOSTI – National Commission for Science Technology and Innovation
PCA – Plate count agar
PDA – Potato dextrose agar
SPSS – Statistical Package for Social Sciences
USA – United States of America VRBA – Violet Red Blue Agar WHO – World Health Organization
OPERATIONAL DEFINITION OF TERMS
Food safety: Assurance that food will not cause harm to the consumer when it is prepared and eaten according to its intended use (FAO/WHO, 2009).
Food borne diseases: Diseases spread through consumption of contaminated food sometimes resulting in appreciable morbidity and occasional mortality.
Good hygiene practices: All practices regarding the conditions and measures necessary to ensure the safety and suitability of food at all stages of food chain.
Hygiene: A continuous process of ensuring that cleanliness is observed and maintained to the required standards.
Homogenate: a homogenized sample mixed so well that removing some of the sample does not alter the overall make-up of the sample remaining. In this study each fruit category per cluster was homogenized.
Indicator organisms: Organisms detected using rapid, non-specific tests to give presumptive evidence for the presence of pathogens. After a positive presumptive test has been obtained, the presence of pathogenic microorganisms can be confirmed using specific detection techniques.
Minimally processed fruits: Those fruits that have undergone only a few unit operations such as washing, peeling, cutting, in preparation for consumption.
Nutrient agar: A widely used general medium containing beef extract and peptone and is suitable for counting microorganisms that grow in food. It uses the assumption that all living (viable) cells in the sample will be able to grow and manifest their presence after cultivation in the suitable medium for growth
“Ready-to-eat” Status of the food being ready for immediate consumption at the point of sale. It could be raw or cooked, hot or chilled, and can be consumed without further heat-treatment including re-heating.
Street foods or street-vended foods: Foods and beverages prepared and /or sold by vendors in the streets and other public places for immediate consumption or consumption at a later time without further processing or preparation. This definition includes fresh fruits which are sold outside authorized markets for immediate consumption. (FAO/WHO 2009).
ABSTRACT
Despite numerous benefits of minimally processed fruits vended as street foods, it has been recognized that they can be a source of foodborne illnesses that can majorly result from poor hygiene practices and unsanitary conditions at fruit vending points. The main objective of the study was to assess the hygiene status and microbial contamination in fruit vending businesses in Nairobi central ward. The study was cross sectional with analytical component and through purposive sampling, 223 willing street food vendors from 7 clusters in the Central ward were selected for the study. Fifty two fruit samples of four fruit categories sold by different vendors in each cluster were pooled and homogenized, and a serving of each fruit typed weighed and analyzed in duplicate in the laboratory. The data collection tools utilized included a structured questionnaire and an observation checklist which were prepared using codex food hygiene and safety principles. Data collected was analyzed using SPSS version 21, Genstat 13th edition and Excel spreadsheet. Chi-square, and Kruskal Wallis tests were used to establish relationship between dependent and independent variables. All the significant tests for the hypothesis were at 95% confidence level (p< 0.05). Food hygiene knowledge and hygiene practice levels were ranked according to Bloom cut off points on calculated scores, where scores were converted to 100%. Based on the sum scores, Food hygiene knowledge and practice was classified as good (>80%); average (60-80%) and poor (0-59%). Food hygiene knowledge and practices were significantly different in the clusters (p>0.05) with vendors in City market and CBD having the highest Food Hygiene Knowledge score while vendors in Uhuru Park and OTC having the highest Food Hygiene Practice score. Hygiene status was not significantly associated (p>0.05) with either food hygiene knowledge or practice. Time period of experience was found to be significantly associated with hygiene status (p>0.05). The major sanitary deficiencies that were identified included no drying racks for cleaned utensils, (55%) lack of uniforms, (54%) vendors wearing jewelry (74%) while working, lack of training, (83%) lack of medical certificates (73%) and cracks and crevices on work surfaces (87%), presence of garbage and waste near stalls, (68%) uncovered dustbins, (95%) and presence of houseflies (25%). Expressed in log10 colony forming units/gram, high bacterial load counts, highest mean (log10 5.32cfu/g) were seen in fruit salad samples. High coliform load counts mean (log10 0.08) were seen in all the fruit samples indicating contamination with fecal matter, while high mold and yeast counts were found in fruit salad and pineapple samples. The null hypothesis was accepted. Compared to other similar studies, low levels of hygiene knowledge and practice were reported. The government should formulate a policy on ready-to-eat food vending as part of street food policy.
CHAPTER ONE: INTRODUCTION
Background information
Fruits are an extraordinary dietary source of micronutrients and fiber for humans and are thus vital for health and wellbeing. Almost 90% of vitamin C originates in fruits (Simitu, 2011). Well balanced diets, rich in fruits are especially valuable for their ability to prevent vitamin C and vitamin A deficiencies and are also reported to reduce the risk of several diseases plus their consumption has become a global priority (McCarthy & Matthews, 1994; Simitu, 2011).
There is an increasing demand for ready-to-eat fresh-cut fruits, which is causing an expansion of the market for minimally processed products, rising over the last years mainly due to the paucity of time, and increasing demand for low-caloric food products with fresh-like characteristics. The practical advantages and convenience they provide to consumers is undoubtedly favorable because they are easily accessible, convenient and most importantly cheaper than whole fruits. (Simitu, 2011) However, because of the specific forms in which they are prepared, they are highly perishable and are associated with new food safety problems both epidemiologically and microbiologically (Artés, Gómez, & Artés-Hernández, 2007; Eni et al., 2010).
In the developing countries, it is considered that the burden of food- borne illness is worse than in the developed countries, as a result of inadequate food safety programs or absence of an organized institutional body for vended street foods (Abeditan, 2011). However, there is little available data, to show the actual magnitude in general, leave alone in relation to minimally processed fruits alone. Many cases of illness go unreported and unrecognized yet these types of illnesses are a significant
contributor to the burden of disease in less developed countries. This therefore highlights the need of applying good hygiene practices from farm to fork to prevent contamination and/or bacterial growth, and ensure compliance with appropriate food safety guidelines and regulations (Sherrae & Neela, 2015). Much research work and surveillance of food borne diseases has been done in Kenya but, the incidences of food borne diseases associated with fruit are not easy to estimate as most of the illnesses are lumped together when recording, as diarrhoeal diseases, which suggest underlying problems in food safety. (Kariuki, 2012; Gizaw et al., 2014).
Street food vending is common in the Central ward of Nairobi County, and fruits are sold either by mobile vendors who hawk them around especially when there is traffic or in offices, or by stationary vendors who are set up in various such strategic places such as stalls, market places and public bus stations. These products are primarily offered as convenience items for those individuals who do not wish to be bothered by or have no time for preparation. They are also sold for immediate consumption, especially during lunchtime. Nairobi Central ward is a location that is convenient and desirable for most fruit vendors because there is enough foot traffic for the vendors to make sufficient sales, and if they were to sell outside the central ward the sales would not be as good (Kamunyori, 2007).
While it is expected that minimally processed fruits sold as street food contribute immensely to the nutritional needs of consumers, it is not easy to ascertain their safety from contaminants especially by microorganisms (Mwangi, 2002; Gitahi., 2012). Experts say fruits are reservoirs of disease causing germs. In recent years, there has been an increase in the number of reported cases of foodborne illnesses linked to fresh fruits (Mc Carthy & Matthews 1994; Madueke et al., 2014).
The fresh nature of these products, coupled with the mild handling and processing techniques, and the storage conditions have presented microorganisms with the potential to grow and multiply and in turn increasing chances of foodborne outbreaks associated with consumption of ready to eat foods (Francis, Thomas, & O’beirne, 1999). Pathogens may also invade the interior surfaces of sliced fruit during washing, peeling, trimming, handling and packaging (Abadias et al, 2008).
Vendors for minimally processed fruits just like all food handlers, have the primary responsibility to guarantee that fruits served are hygienic and safe for consumption. But intentional or inadvertent contamination of fruits puts the consumer at the risk of suffering foodborne illnesses (Monica, 2011). It is against this background that the study was carried out to address the various aspects of hygienic practices like preparation skills, handling, storage, place of preparation, storage of leftovers, and also to establish the microbial load of these minimally processed fruits.
Problem statement
The increase in consumer needs for fresh products with subsequent increase in street vending of minimally processed fruits is increasingly offering challenges to both health of consumers and local authorities as there is no proper control in this informal sector. Poor hygiene practices therefore, coupled with low standards of environmental and personal hygiene, improper handling of food, improper storage occur with street foods raising health concerns such as foodborne illnesses (Kariuki, 2012).
In Nairobi Central Ward the street food industry plays an important role where it feeds millions of people daily with a wide variety of foods that are relatively cheap and easily accessible. In the markets and bus stations, a wide variety of fruits that offer cheap snacks are sold. Due to increased demand for resources coupled the
unlimited and unregulated growth, there has been a severe strain on city resources such as water, sewage systems, and interference with city plans through congestion and littering. Street food vendors are usually unlicensed blocking vehicle and pedestrian traffic (Muinde & Kuria, 2005; Monica, 2011). This raises concern with respect to their potential for serious food poisoning outbreaks and exposure of the sliced fruits to flies, dust and other disease causing agents.
Few studies have been done in this context and especially in determining the hygiene and safety of minimally processed ready-to-eat fruits in Nairobi central ward which also hosts the CBD.
Justification
Fruits are increasingly becoming important dietaries in Kenya, and are assumed to be safe and healthier for consumption because they are mildly handled. In Nairobi, they are found to be sold in many areas where people operate like in the markets, stalls and side-roads. However, the hygienic preparation and microbial contamination of these products are not well established.
The need for this study arose from lack of information on fruit microbial contamination levels, and food hygiene practices. There is also general lack of knowledge about the microbiological status or the precise epidemiological significance of minimally processed fruits, and therefore was necessary to carry out research in order to highlight the health implications of consuming such ready-to-eat fruits, and recommend any necessary interventions that could be adopted by the relevant bodies or authorities in improvement of hygiene of street vended fruits.
Research questions
- What is the food hygiene knowledge and hygiene practices of the fruit vendors?
- What are the hygienic conditions of the fruit preparation and vending environment?
- What is the microbial status of minimally processed fruits?
Hypothesis
Minimally processed fruits sold as street foods are not prepared and vended under hygienic conditions and therefore are a threat of microbial contamination
Main objective
To assess the hygiene and status of microbial contamination, of minimally processed fruits sold as street foods in Nairobi.
Specific objectives
- To establish food hygiene knowledge and practices of the fruit vendors
- To determine the hygiene conditions of the fruit preparation and vending environment
- To determine the microbial status of minimally processed fruits.
Conceptual framework
Figure 1.1 is a model that elaborates on factors that can affect hygiene and safety of fruits in public places and inter relates the major variables involved in this study. The dependent variable is fruit safety and quality while the independent variables are environmental factors such as hygiene and physical condition of the fruit vending
environment; personal factors such as fruit hygiene knowledge and practice; and physiological factors such as microbial contamination.
Food safety is the assurance that food will not cause harm to the consumer when it is prepared and eaten according to its intended use (WHO/FAO 2012). Food borne illnesses that occur can therefore be as a result of microbial contamination during harvesting, transporting, packaging or distribution and also as a result of poor handling by the workers, or use of dirty equipment. Fruits can easily be contaminated either by the host who in this case could be the food handler or the consumer; microorganisms from production to consumption and the environment which includes factors such as temperature, humidity, air pollution, water etc.
