Fungal quality of fresh shrimp collected from Ndibe-Beach in Afikpo North Local Government Area of Ebonyi State, Nigeria was investigated by standard microbiological procedures. The shrimp was found to be contaminated with five fungal isolates belonging to different genera at varying loads; Aspergillus species, Penicillium species, Mucor species, Fusarium species and Rhizopus species. Samples of the head, body and tail showed an average fungal load of 2.07x106, 0.39x106 and 0.79x106 respectively. The percentage of occurrence showed that Aspergillus species have the highest frequency of 8(25.0%) for vendor A, 7(28.0%) for vendor B and 7(27.0%) for vendor C while Rhizopus species have the lowest frequency of occurrence of 4(12.5%), 4(16.0%) and 3(11.5%) for vendors A, B and C
respectively. The presence of these fungi on the shrimp is attributed to contamination from the environment and from shrimp handlers. Also, some of these fungi are normal flora of the shrimp which unfortunately happens to be opportunistic pathogens or pathogens of humans. The maintenance of high personal and environmental hygiene as well as proper heating and cooking will improve fresh shrimp quality and prevent food-borne diseases.
TABLE OF CONTENTS
Title page - - - - - - - - i
Certification - - - - - - - - ii
Dedication - - - - - - - - iii
Acknowledgement - - - - - - - iv
Table of Contents - - - - - - - v
List of Tables - - - - - - - - viii
List of Figures - - - - - - - ix
Abstract - - - - - - - - x
CHAPTER ONE
1.0 Introduction - - - - - - - 1
1.1 Statement of Problem - - - - - - 3
1.2 Aim - - - - - - - - 4
1.3 Objectives - - - - - - - 4
1.4 Significance of Study - - - - - - 4
CHAPTER TWO
2.0 Literature Review - - - - - - - 5
2.1 Background Information about Shrimp - - - - 5
2.1.1 Scientific Description of Shrimp - - - 6
2.1.2 Scientific Classification - - - - 7
2.1.3 Other species - - - - - - 7
2.2 Shrimp Farming - - - - - - 8
2.3 Normal Microbiota of Shrimp - - - - - 8
2.4.0 Importance of Shrimp - - - - - 9
2.4.1 Shrimp as Food - - - - - - 9
2.4.2 Medicinal use - - - - - - 11
2.5 Microbial Contamination or Spoilage of Shrimps - - 11
2.6 Fungi - - - - - - - - 12
CHAPTER THREE
3.0 Materials and Methods - -
CHAPTER ONE
INTRODUCTION
Shrimp is a small free-swimming edible crustacean with 10 legs. It is basically marine commonly found in estuaries and along coastal waters. However, its primary habitat is muddy bottom areas from intertidal zone to approximately 110m with greatest density occurring at depth between 27 to 55m (Williams, 1984).
Shrimps are scavengers generally termed bottom-feeding opportunistic omnivores, which means they feed on most organic materials- dead plants or animal matter that they encounter at the bottom. They consume some algal species (that is, filamentous green algae, benthic diatoms, and plant detritus) invertebrates such as copepods, mollusks, and annelids (Dall, 1968; Odum and Herald, 1972).
Shrimp has high nutritional value especially protein of 41% (W/W) and omega-3 fatty acids which have anti-inflammatory effects and are able to prevent the formation of blood clots. They are also important sources of vitamin D and B12 needed to keep low levels of homocysteine -a molecule that can directly damage blood vessel walls and is considered a significant risk factor for cardiovascular diseases.
Crustacean constitutes an important food component for a large section of the world population, more so in developing countries where shellfish forms a cheap source of protein (Din et al., 2004).
Among the range of shellfish, shrimps and crabs are the most important, thereby accounting for more than 70% of the total earnings of marine export products (Anthony et al., 2002). Shellfish are nutritionally balanced, an excellent source of proteins, a good source of minerals and source of vitamins and are also low in fats and cholesterol (Ifon and Umoh, 1987). Shrimps have been used by riverine dwellers in Niger Delta as food condiments and are recommended for pregnant women and protein malnourished cases. They are also known to reduce the risk of coronary heart disease, and are used in weight control and other disorders including cancer (Ekpo and Uzegbu, 2004; Larson et al., 2004; Din et al., 2004).
A survey of the microbiological quality of some shellfish has shown that shrimps harbour pathogenic organisms (Adebayo- Tayo et al., 2006) bacteria and fungi.
These pathogenic organisms have been implicated in the outbreak of food-borne disease in many parts of the world. They include typhoid, hepatitis and similar disorders of the digestive system (Spancer and Cutting, 1968).
Aquatic organisms in general accumulate contaminants from the environment and therefore, have been extensively used in marine pollution monitoring programmes (Uthe et al., 1991).
Heavy metals discharged into the marine environment can damage both marine species diversity and ecosystem, dare to toxicity and accumulative nature of the metals.
Hence, there is need to check microbial and chemical contaminants in foods from the aquatic environment in order to understand their hazard levels and thus creating awareness to the public on health risks in consuming raw or undercooked and under-processed shellfish such as shrimps.
A part from Penaeus azteeus, other species include: Penaeus monodon, Penaeus indicus and Penaeus vannamei.
1.1 Statement of problem
Microorganisms are known to be everywhere.
Many of them such as bacteria and fungi are pathogenic to human health. These pathogens can be haboured by shellfish such as shrimps which may be implicated in the outbreak of food-borne disease among the consumers in the Niger Delta region of Nigeria.
1.2 Aim
This study was conducted to determine the fungal quality of shrimp.
1.3 Objectives
To determine the fungal load of edible shrimp.
To isolate and identify the microorganisms (pathogenic fungi) in head, body and tail of fresh shrimp.
To determine the percentage frequency of distribution of the isolates.
1.4 Significance of study
This study will be useful to reverine dwellers, pregnant women and consumers of shrimps.
The outcome of this research will guide consumers of this seafood on the best method of handling and preparation, to avoid contamination which will lead to food-borne disease outbreaks; the research work also will add to the literature and information existing about shrimps for students and industries that use shrimps as raw materials for the production of food.
CHAPTER TWO
2.0 LITERATURE REVIEW
No comments:
Post a Comment