Fungi Associated With Spoilage of Smoked Dried Fish
Chapter One
Aims/Objectives of the study.
The aim of the study is to investigate the fungi associated with spoilage of smoked dried fish. Specifically, the objective of the study is to;
- Isolated the fungi’s associated to smoked dried fish vended in Eke-Awka market.
- To identify the fungi associated to smoked dried fish.
CHAPTER TWO
LITERATURE REVIEW
Fungi are parasitic, that is they rely on a nutritional supply from a host (you) in order to survive. Without carbohydrate, they will soon perish. Carbohydrates are foods that produce sugar upon digestion. It is also important to re-establish good bacteria in the bowel(Ogbonna,2013). The bowel is an entire ecosystem containing good bacteria and harmless yeasts. A disruption within this ecosystem is called dysbiosis. Normally your intestinal ecosystem serves two functions. It protects and defends. When you take antibiotics, birth control pills and cortisone, they negatively impact this ecosystem. If you have taken any of these you need to supplement with “good bacteria”. Health food stores carry probiotics in pill or powder form. It is impossible to restore your health without restoring the integrity of the intestines.
Microbial tests of fish and fish products are used by the industry for contractual and internal purposes and by the authorities to check that the microbiological status is satisfactory (Jay, 2015). The micro-flora in which fungi are a part consists of the microorganisms that normally live with the animals. Studies on microflora count and characterization are many in order to establish a baseline that is satisfactory for the consumption populace. Such microflora isolation studies have been reported by Martin (2011), Olawale et al. (2015), Adesokan et al. (2015), and Abolagba and Igbinevbo (2010) for smoked fish (Clarias spp) sold in markets in Benin Nigeria. It is generally accepted that fish with microbial load greater than106cfu/g is likely to be at the stage of being unacceptable from the microbiological point of view and unfit for consumption (Cheesbrough, 2010). Akise et al. (2013) reported that high microbial load and unfavourable composition from smoke-dried Lutjanus agennes (Red Snapper), Mugil cephalus (Mullet) and Chrysichthys walkeri (Catfish) during shelf storage poses a serious health concern for consumers and public health workers.
Microbial Activities of Fungi
According to Josphus,(2011), fungi play a huge role in the breakdown of plant and animal matter and return it to the soil to be used again. Researcher has shown that the number of identified fungal species approaches 100,000, and it is estimated that there may be more than 1.5 million that have yet to be recognized( Musa,2015). Yeasts are single-celled organisms, whereas moulds and mushrooms are groups of cell clustered together. They can reproduce either by sexually- by sharing DNA, dividing and growing- or asexually, either by releasing spores into the environment that form new fungi, or by budding new yeast cells from a parent cell. Spores can lay dormant for many years until the condition are favorable for them to multiply.
Microbial Spoilage of Food
Composition of the microflora on newly caught fish depends on the microbial contents of the water in which the fish live. Fish microflora includes bacterial species such as Pseudomonas, Alcaligenes, Vibrio, Serratia and Micrococcus (Gram and Huss, 2010). Microbial growth and metabolism is a major cause of fish spoilage which produce amines, biogenic amines such as putrescine, histamine and cadaverine, organic acids, sulphides, alcohols, aldehydes and ketones with unpleasant and unacceptable off-flavors (Dalgaard et al., 2016; Emborg et al., 2015; Gram and Dalgaard, 2012). For unpreserved fish, spoilage is a result of Gram-negative, fermentative bacteria (such as Vibrionaceae), whereas psychrotolerant Gram-negative bacteria (such as Pseudomonas spp. and Shewanella spp.).
Microbial spoilage impedes at a recommended storage temperature of -9 to -12°C. However, enzyme present in the fish will still play an important part in spoilage. About 10-60% of the viable microbial population die during freezing yet the remaining population gradually increase during frozen storage (Rahman, 2014). Morlier et al. (2010) reported that Anasakis simplex, a nematode found in certain fish, can be killed by freezing to -20°C and holding at least 24 h. Raj and Liston (2009) reported that only a 1 log10 reduction in numbers of Salmonella typhimurium when fish was frozen at -22°C and stored at -17.9°C for over 1 year. Miladi et al. (2011) found that freeze storage of L. monocytogenes in salmon does not decrease the potential survival of food-borne pathogens over a period of ten months at freezing temperature of -20°C.. Arannilewa et al. (2005) investigated the effect of duration of freeze storage on the chemical, microbiological and sensory profile of tilapia fish (Sarotherodun galiaenus). They reported decreases in the values of protein and fat by 27.9 and 25.92%, respectively. The total coliform count was increased from 3.0×103 -7.5×106 during storage
Yeasts fungi are opportunistic organisms. This means that, as intestinal bacteria die, yeasts thrive, especially when their dietary needs are met. They can use their tendrils, or hyphae, to literally poke holes through the lining of your intestinal wall. This results in a syndrome called leaky gut. Yeasts are not the only cause of this syndrome. Some scientists have linked non-steroidal and anti-inflammatory drugs as well as antibiotics( webmer,2014).
Anatomy of Fungi Organism
Fungal cells are overall very similar to human cells in that not only do they contain a nucleus with DNA, but they also share many of the same physiologic and biologic pathways required for growth and reproduction. They are more closely related to human cells, based on function and gene content than either viruses or bacteria(Hassan,2016).This similarity to human cell poses a challenge to researchers in that it is difficult to find a drug that will selectively kill the fungus and not the human. Another challenge is that fungal cells can be confused for either normal human blood cells or even malignant cancer cells. Without the proper staining techniques by microbiologists and pathologists, the identification of fungal organisms can be entirely missed. Treatment errors may then follow. It is possible to receive an antiobiotic for an infection when what you require is an antifungal. In fact the antiobiotic only worsens the fungal infection by destroying our intestinal bacteria that normally serves to protect against yeast overgrowth.
In a study of mycoflora of smoked–dried fishes sold in Uyo, Eastern Nigeria by Adebayo–Tayo et al; (2015),listed 12 different fungi associated with the smoked–dried fish samples. The associated fungi were:
- Aspergillus flavus
- Aspergillus tereus
- Aspergillus fumigatus
- Absidia sp
- Rhizopus sp
- Aspergillus niger
- Mucor sp
- Clasdosporium sp
- Penicillium italiculum
- Viridatus
- Candida tropicalis
- Fusarium moniliformis
Scientific Classification of Fungi
Kingdom: Fungi
Division: Ascomycota
Class: Eurotiomycetes
Order: Eurotiales
Family: Trichocomaceae
Genus: Aspergillus
Species: A. spp
CHAPTER THREE
MATERIALS AND METHOD
Sample Collection
The Four fish samples used for the study were purchased from four different location A,B,C and D in Eke-Awka market which is the largest market in Awka, named after one of the four market days. It is Located on a former community burial ground in the center of the city. Eke Awka has grown from a small market serving the needs of residents of the Agulu, Ezi-Oka and Amikwo sections of Awka to functioning as the main retail outlet for the city and neighbouring towns. It houses an estimated 5,000 lock-up shops and stalls all tightly packed into less than 35,000 square meters of space and has become infamous for causing tremendous traffic chaos with a medley of shoppers, buses, wheel barrows all jostling for the limited amount of space available.
Equipment Used
The equipment’s used in carrying out the study are as follows;
Test tube
Text tube rack
Conical Flask
Electric blender
Autoclave
Cork borer
Microscope
Inoculating loop
Reagent Used
The reagents used are as follow; Distill water and Ethanol
CHAPTER FOUR
RESULT AND DISCUSSION
The result of the finding is shown presented in the table shown below
Table 1: Fungi isolated from the sample collected from four location in Eke- Awka Market
CHAPTER FIVE
DISCUSSION, CONCLUSION AND RECOMMENDATION
Discussion
Findings of the study indicated that various fungi organism are associated to smoked dried fish samples and this fungi are responsible for the degradation and micro toxin contamination of most food such as fish. Some of this fungi ranges from Fusarium germanium, Aspergilius niger, Fusarium hair, and asprgilius fumigatus. The finding of the study also corroborate with the findings of Such Martin (2011), Olawale et al. (2015), Adesokan et al. (2015), and Abolagba and Igbinevbo (2010) for smoked fish (Clarias spp) Akise et al. (2013) reported that microflora isolation from fish sample high microbial load and unfavourable composition from smoke-dried Lutjanus agennes (Red Snapper), Mugil cephalus (Mullet) and Chrysichthys walkeri (Catfish).
The findings also showed the contamination of this fish samples are due to the method of processing, unhygienic condition and exposure in the market place to contaminated air and materials. The findings also indicate that that the contamination of this samples under favorable condition like temperature and moisture, the fungi causes great reduction in weight of the fish samples due to degradation. This findings agree with the findings of Josphus,(2011) who said fungi play a huge role in the breakdown of plant and animal matter and return it to the soil to be used again.
Conclusion
Evidence from the study have shown that there are fungi associated with smoked dried fish and those fungi possess mycotoxins that pose danger to human and animal health as they are toxic to vertebrates and other animals in low concentrations. The implication of this is that most consumers might have been consuming these metabolites and their prolonged intake may constitute a health hazard. In other to demonstrate that a disease is a mycotoxicoses, it is necessary to show a dose- response relationship between the mycotoxin and the disease which this study to has evidently shown. Hence, it can be said that most of the smoked dried fish vended in Eke Awka contain some level of fungi contamination
Recommendation
Based on the findings of the study, it is recommended that proper care should be taken by fish vendor during processing and sell. Fish meant for consumption should be properly washed and boiled in other to kill any presence of fungi and it micro toxin.
REFERENCES
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