Microbial Profile of Spoilt Egusi (Citrullus Colocynthis)
Chapter One
AND OBJECTIVE OF THE STUDIES
The aims and objective of this topic; Microbial profile of spoilt Egusi “Citrullus colocynthis l.” are as follow:
To determine the microbial load of spoilt Egusi
To isolate the microorganism associated in the spoilage of Egusi.
To identify and characterize the isolated organisms.
CHAPTER TWO
LITERATURE REVIEW
ORIGIN, DISTRIBUTION, AND ECOLOGY
Citrullus colocynthis l., with many common names including colocynth, bitter apple, bitter cucumber, desert gourd, egusi, vine of Sodom, or wild gourd, is a desert viny plant native to the Mediterranean Basin and Asia, especially Turkey (especially in regions such as İzmir), Nubia, and Trieste. It resembles a common watermelon vine, but bears small, hard fruits with a bitter pulp. It originally bore the scientific name Colocynthis citrullus l. (Eidi et al., 2015). colocynthisis a desert viny plant that grows in sandy, arid soils. It is native to the Mediterranean Basin and Asia, and is distributed among the west coast of northern Africa, eastward through the Sahara, Egyptuntil India, and reaches also the north coast of the Mediterranean and the Caspian Seas. It grows also in southern European countries as in Spain and on the islands of the Grecian archipelago. On the island of Cyprus, it is cultivated on a small scale; it has been an income source since the 14th century and is still exported today. It is an annual or a perennial plant (in wild) in Indian arid zones and has a great survival rate under extreme xeric conditions (Lloyd and John, 1898). In fact, it can tolerate annual precipitation of 250 to 1500 mm and an annual temperature of 14.8 to 27.8 °C. It grows from sea level up to 1500 meters above sea level on sandy loam, subdesert soils, and sandy sea coasts with a pH range between 5.0 and 7.8 (Citrulus colocynthis, 2012).
Egusi Citrullus colocynthis l. is a species of melon native to tropical Africa (west of the east Africa rift) where it is grown for food and as a source of oil. It is also known as white melon seed.
Citrullus colocynthis manni is a member of the cucurbitaceae family. This crop is often referred to as “Egusi” given to its long history in West Africa, dating back 4000 years. This plant is basically harvested for its large white seeds called Egusi-itoo. The seeds are commonly processed into soups and oil products and also eaten individually as a snack.
If produce climbing vines up to 4 meters long which are covered in stiff hairs. Then it bears small yellow male and female flowers with petals under a centimeter in length, the heart, shaped or roughly palmate leaves are up to 12 centimeter long and 14 centimeter wide. The fruit is egg shaped, up to about 18 centimeter long and 8 centimeter wide, and cream in colour with green streaks. The fruit and white seeds are edible. Colocynthis citrullus can survive in harsh climates and high yields are attainable in barren landscape.
CHARACTERISTICS AND MORPHOLOGY
Roots and stems
The roots are large, fleshy, and perennial, leading to a high survival rate due to the long tap root. The vine-like stems spread in all directions for a few meters looking for something over which to climb. If present, shrubs and herbs are preferred and climbed by means of axiliary branching tendrils (Lloyd and John, 1898).
CHAPTER THREE
MATERIALS AND METHODS
MATERIALS
The materials used for the study are;
Petri dish, Conical flask, Measuring cylinder, Pipette, Glass slide, Test tube, Wire loop, Force-p, Bio hazard wares, Autoclave, Hot air oven, Incubator, Pressure cooker, Digital colony counter.
REAGENTS USED
Reagents used are;
Normal saline, Kovac’s reagent, Oxidase reagent, Hydrogen peroxide, Plasma
Citrate identification tablets, Iodine, Saffranine, Ethanol, Crystal violet, Lactophenol cotton blue
MEDIA USED
Media used for the study are
SABOURAUD AGAR: is a type of agar containing peptones. It is used to cultivate dermatophytes and other types of fungi.
NUTRIENT AGAR: This is a general purpose agar used for culturing non-fastidious microorganisms. The powder is a pale-yellow and on addition of water forms clear yellow solutions its PH is about 7.3.
MAC-CONKEY AGAR: This medium differentiates lactose fermenters from non lactose fermenters. lactose fermenters produce redish colours. In this medium, lactose serves as the sole carbon source. The bile salts and crystal violet in this medium inhibit the growth of gram negative bacteria.
CHAPTER FOUR
RESULT
Table 3.1, shows the total microbial count which ranges from 1.2 X 1010 – 2.8 X 1010 cfu/g (for Total Heterophilic Bacteria Count), 7.8 X 109 – 9.8 X 109cfu/g (Total Coliform count), and 1.6 X 1010 – 1.7 X 1010 cfu/g (Total Fungi count).
CHAPTER FIVE
DISCUSSION AND CONCLUSION
DISCUSSION
Microbial spoilage of food can results as the growth and activities of microorganisms (bacteria, yeasts and molds), activities of food enzymes and other chemical reactions within the food itself, infestation by insects (parasites and rodents), inappropriate temperature for a given food either the gain or loss of moisture, reaction with oxygen, exposure to light, physical stress or abuse and time. The presence of microorganism in food can be during food processing and handling. The high coliform counts are an indication of poor sanitary practices in the production of these samples (ICSMF, 1906). These could be explained to mean that effective quality control of the production processes of these foods are necessary to help reduce/eliminate contaminants, some of which could be pathogenic. The presence of diverse species of bacteria and fungi in Egusi samples corroborate the findings of some other research works that implicated diverse bacterial and fungal species in foods and food condiments which can cause spoilage (Obadoni and Ochuko, 2001). The presence of bacillus species in Egusi could be explained by the fact that bacillus species are spore bearers that frequently inhabit dust particles, natural water, vegetation, sediments and many foods. Some bacillus species e.g. B. anthraces, B. cereus are known to be pathogenic, however, majority of bacillus species are food spoilage organisms or opportunistic pathogen. The isolation of B. spp. from Egusi may not be a cause for concern because it rarely causes food poisoning and have been used as a probiotic (Ryan and Ray, 2004) and also involved in fermentation.
The isolation of E. coli, Klebsiella spp. and Salmonella spp. the samples indicates poor sanitary standard post processing. Although some strains of these organisms have been used as probiotic and are known to play a role in food fermentation, they are indicators of faecal contamination and have been implicated in food spoilage. Staphylococcus spp. in Egusi could be from equipment, food contact surfaces or human contamination of product post processing. It is a normal flora of man and some enterotoxin producing strains cause food poisoning specifically when there is temperature-time abuse. The isolation of mould species Rhizopus, Mucor, Penicillin, and Aspergillus from the samples could be explained by the fact that moulds are spore bearers and common environmental contaminants often isolated from food and food products. Rhizopus, Mucor, Penicillin, and Aspergillus are common saprobic fungi found on a wide variety of organic substrates, they are common agents in fruits spoilage (Loir Y.L., et al., 2003).
CONCLUSION
In conclusion, Egusi that is not properly produced and preserved should be disposed and food handlers should handle food products with care as well as practice hygiene to keep products their environment clean. These consumers are as well advised not to consume improper prepared and preserved Egusi and should also make sure they produce it properly and preserve and sell it proper too with clean containers and environment (Bevechat 2008).
RECOMMENDATION
Correct food handling practice and food storage helps prevent bacteria from contaminating and multiplying on foods. The following action needs to be taken to prevent bacterial contamination: Protect food from contamination – handle food properly, Prevent bacteria from multiplying, Destroy germs on/in food. Food can be protected from contamination by handling it with care. Food handlers should think about: where food poisoning bacteria come from. They can come from people’s bodies, sneezes, coughs, high risk foods, insects, rodents, pets, toilets and dust particles in the air, the different ways bacteria can get on to the food they are handling, for example, from cross contamination and, contaminated hands and clothing, the correct cooking and storage temperatures which prevent bacteria multiplying.
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