ABSTRACT
The analysis was carried out to determine the microbial load on African oil bean. The Total Heterophilic Bacteria Count recorded ranges from 1.2 X 1010 – 2.8 X 1010 Cfu/g and the Total Coliform count ranges from 7.8 X 109 – 9.8 X 109Cfu/g and the Total Fungi Count obtained ranges from 1.6 X 1010 – 1.7 X 1010 Cfu/g. Five genera of bacteria were isolated which are salmonella, Staphylococcus, Escherichia coli, Bacillus, and Klebisiella. Fungal isolates were Rhizopus spp., Aspergillus spp., mucor spp., and Penicillium spp. 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 production of these samples.
CHAPTER ONE
1.0 INTRODUCTION/LITERATURE REVIEW
1.1 INTRODUCTION
Agbarati also known as “Usu” is an indigenous meat analogue produced mainly in the rural areas of South Eastern Nigeria. It is generally understood as melon cake. Melon cakes are sometimes mixed with cooked sliced fermented oil bean fruit called “Ugba” in Ibo and cooked with stockfish (Nwokoma, 2008). This local delicacy is a steamed product obtained after blending uniformly melon seeds (Colocynthis citrullus) and “Erousu” (Sclerotus tuber-regium) with the addition of other ingredients (Pepper, Onions, Salt, Warm water and Seasoning). It is eaten as asnack and is often added to vegetable soups as a meat substitute. In some rural parts of Nigeria, melon seed meal is compacted into patties that serve as a meat substitute (Ogunsua, 2000).
In Imo State, it is called “Agbarati”, in Umuahia “Ngbam”, in Onitsha, “Agbaghelu atui” and understood in the Ibo tribe as “Akpuruakpu Egusi”. Melon seeds are pounded and used in the preparation of popular steamed snack known as “Agbaghelu atui” (Onitsha) (Nwokoma, 2008). They are molded into balls of various shapes (round, flattened or cylindrical) with the colour of its balls ranging from dark brown to light grey. Health wise, the meat analogue is important to the diet because they provide the body with proteins, fiber and other essential micronutrients (Decker, 2004). David and Aderibigbe (2010) stated that its composition shows: Moisture content of 40%, Ash content of 14%, Crude fiber of 2.40%, 20% fat, 10.50% protein and Carbohydrate of 10.60 %. It has a shelf life of 24hours at ambient temperature (Akobundu et al., 1982; Nwakaudu, 2010).
The preservation of Agbarati-Indigenous meat analogue has been tried using such methods as drying and packaging material (Nwakaudu, 2010) but no work has been done on the use of chemical preservative methods to extend the shelf life of Agbarati.
This product has a problem of deteriorating easily after 24 hours when kept under ambient temperature, it loses its taste, becomes slimy and mold infested. As a result of this problem, Agbarati has remained a remote product whose production has not been incorporated into an industrial scale. Its major raw material (melon seeds) has poor storage problems. At local levels however, stored melon seeds do
not keep well possibly owing to poor processing and storage technique (Adegoke and Ndife, 1993). Therefore, there is need to extend the shelf life of melon seeds through processing and use of food grade chemical preservatives so as to make it available all year round. This would also help to reduce the high cost of melon seeds during off seasons having its product as a meat analogue (Decker, 2004). Agbarati is a good substitute to meat in vegetable soups especially for Vegetarians. Also, being a proteinous food, the success of its preservation will go a long way in boosting the Nigerian economy since its counterpart (animal protein) is very expensive.
1.2 AIM AND OBJECTIVES
The aim of this study is to evaluate the microbial load on agbarati.
Objectives
- To isolate microorganisms from agbarati
- To characterize the organisms associated with agbarati
1.3 LITERATURE REVIEW
1.3.1 BACKGROUND OF STUDY
Agbarati also known as “Usu” is an indigenous meat analogue produced mainly in the rural areas of South Eastern Nigeria. It is generally understood as melon cake. Melon cakes are sometimes mixed with cooked sliced fermented oil bean fruit called “Ugba” in Ibo and cooked with stockfish (Nwokoma, 2008).
Melon seeds are pounded and used in the preparation of popular steamed snack known as “Agbaghelu atui” (Onitsha) (Nwokoma, 2008). They are molded into balls of various shapes (round, flattened or cylindrical) with the colour of its balls ranging from dark brown to light grey. Health wise, the meat analogue is important to the diet because they provide the body with proteins, fiber and other essential micronutrients (Decker, 2004). David and Aderibigbe (2010) stated that its composition shows: Moisture content of 40%, Ash content of 14%, Crude fiber of 2.40%, 20% fat, 10.50% protein and Carbohydrate of 10.60 %. It has a shelf life of 24hours at ambient te mperature (Akobundu et al., 1982; Nwakaudu, 2010).
The preservation of Agbarati-Indigenous meat analogue has been tried using such methods as drying and packaging material (Nwakaudu, 2010) but no work has been done on the use of chemical preservative methods to extend the shelf life of Agbarati.
This product has a problem of deteriorating easily after 24 hours when kept under ambient temperature, it loses its taste, becomes slimy and mold infested. As a result of this problem, Agbarati has remained a remote product whose production has not been incorporated into an industrial scale. Its major raw material (melon seeds) has poor storage problems. At local levels however, stored melon seeds do
not keep well possibly owing to poor processing and storage technique (Adegoke and Ndife, 1993). Therefore, there is need to extend the shelf life of melon seeds through processing and use of food grade chemical preservatives so as to make it available all year round. This would also help to reduce the high cost of melon seeds during off seasons having its product as a meat analogue (Decker, 2004). Agbarati is a good substitute to meat in vegetable soups especially for Vegetarians. Also, being a proteinous food, the success of its preservation will go a long way in boosting the Nigerian economy since its counterpart (animal protein) is very expensive.
Citrullus colocynthis, 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 (Eidi et al., 2015).
1.3.2 ORIGIN, DISTRIBUTION, AND ECOLOGY
- colocynthis is 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, Egypt until 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).
1.3.3 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).
Leaves
Very similar to watermelon, the leaves are palmate and angular with three to seven divided lobes.
Flowers
The flowers are yellow and solitary in the axes of leaves and are borne by yellow-greenish peduncles. Each has a subcampanulated five-lobed corolla and a five-parted calyx. They are monoecious, so the male (stamens) and the female reproductive parts (pistils and ovary) are borne in different flowers on the same plant. The male flowers’ calyx is shorter than the corolla. They have five stamens, four of which are coupled and one is single with monadelphous anther. The female flowers have three staminoids and a three-carpel ovary. The two sexes are distinguishable by observing the globular and hairy inferior ovary of the female flowers (Lloyd and John, 1898).
Fruits
The fruit is smooth, spheric with a 5– to 10-cm-diameter and extremely bitter taste. The calyx englobe the yellow-green fruit which becomes marble (yellow stripes) at maturity. The mesocarp is filled with a soft, dry, and spongy white pulp, in which the seeds are embedded. Each of the three carpels bears six seeds. Each plant produces 15 to 30 fruits (Citrullus colocynthis, 2012).
Seeds
The seeds are grey and 5 mm long by 3 mm wide. They are edible but similarly bitter, nutty-flavored, and rich in fat and protein. They are eaten whole or used as an oilseed. The oil content of the seeds is 17–19% (w/w), consisting of 67–73% linoleic acid, 10–16% oleic acid, 5–8% stearic acid, and 9–12% palmitic acid. The oil yield is about 400 l/hectare. In addition, the seeds contain a high amount of arginine, tryptophan, and the sulfur-containing amino acids (Gunideeban et al., 2010).
Cultivation
- colocynthis, a perennial plant, can propagate both by generative and vegetative means. However, seed germination is poor due to the extreme xeric conditions, so vegetative propagation is more common and successful in nature. In the Indian arid zone, growth takes place between January and October, but the most favorable period for the vegetative growth is during summer, which coincides with the rainy season. Growth declines as soon as the rains and the temperature decrease and almost stops during the cold and dry months of December and January (Agahiu et al., 2011). Colocynth prefers sandy soils and is a good example of good water management which may be useful also on research to better understand how desert plants react to water stress. To enhance production, an organic fertilizer can be applied. Colocynth is also commonly cultivated together with cassava (intercropping) in Nigeria (Agahiu et al., 2011).
Cultivated colocynth suffers of climatic stress and diseases such as cucumber mosaic virus, melon mosaic virus, Fusarium wilt, etc. as any other crop. To improve it, a relatively new protocol for regeneration has been developed with the aim of incorporating disease and stress resistance to increase yield potential and security avoiding interspecific hybridization barriers (Ntui et al., 2009).
Uses
- colocynthis can be eaten or elaborated for further uses in medicine and as energy source, e.g. oilseed and biofuel. The characteristic small seed of the colocynth have been found in several early archeological sites in northern Africa and the Near East, specifically at Neolithic Armant, Nagada in Egypt; at sites dating from 3800 BC to Roman times in Libya; and the prepottery Neolithic levels of the Nahal Hemar caves in Israel. Zohary and Hopf speculate, “these finds indicate that the wild colocynth was very probably used by humans prior to its domestication.”
Medical study
Clinical studies have shown medicinal benefits of colocynth in patients with diabetes, diabetic neuropathy, and hyperlipidemia. In a randomized clinical trial (RCT), HbA1c and fasting blood glucose levels were decreased in patients using 300 mg of C. colocynthis dry fruit powder daily for 2 months. In another trial, intake of 300 mg of powdered seed can lower the triglyceride and cholesterol concentration significantly in nondiabetic hyperlipidemic patients (Rahbar and Nabipour, 2010).
Topical C. colocynthis also showed significant efficacy in treatment of patients with painful diabetic neuropathy in another RCT; the application of a topical formulation of C. colocynthis fruit extract can decrease the pain and improve nerve function and quality of life in patients with painful diabetic neuropathy (Heydari et al., 2015).
Colocynth has been widely used in folk medicine for centuries. Johann Weyer, in De praestigiis daemonum (1563), offers it as a cure for lycanthropy. Interest in its anti-inflammatory properties has been renewed in modern times.
Aqueous and methanol extracts of colocynth showed high antimicrobial activity against Escherichia coli, Staphylococcus aureus, and other bacteria. Extracts of fruits, leaves, roots and stems were also found to be potentially usable against many Gram positive bacilli and fungi such as Aspergillus fumigatus, Aspergillus flavus, and Mucor species.
In addition, some of these extracts were found to have an insulin tropic effect and therefore an antidiabetic effect, which may make them relevant to the treatment of diabetes mellitus (Gurudeeban et al., 2010).
Cucurbitacin glucosides seem potentially important for therapy against breast cancer cells because of their ability to modify cell morphology and signaling, and to induce apoptosis and changes in mitochondrial membrane potential (Tannin-spitz et al., 2007).
Another property of colocynth is hair growth stimulation: an experiment on rats demonstrated that hair growth initiation time was significantly decreased after treatment with colocynth petroleum ether extracts (Roy et al., 2007).
Before modern medicinal uses
In pre-modern medicine, it was an ingredient in the electuary called confectio hamech, or diacatholicon, and most other laxative pills; in such cases as required purging, it was very successful. It is one of the most violent purgative drugs known; insomuch that it excoriates the passages to such a degree as to sometimes draw blood and induce a so-called “superpurgation”. Sometimes, it was taken boiled in water, or beer, in obstruction of the menses, which was considered successful in strong constitutions. Some women used it in the same manner, in the beginning of pregnancy, to cause an abortion, which often occurred due to the violence of its operation. Its use for this purpose is documented in ancient times; for example, the following recipe was found in the Ebers medical papyrus in Egypt, dated to about 1550 BCE: (Davis and Company Parke, 1909)
“To cause a woman to stop (terminate) pregnancy in the first, second, or third period [trimester]: unripe fruit of acacia; colocynth; dates; triturate with 6/7th pint of honey. Moisten a pessary of plant fiber (with the mixture) and place in the vagina.”
The powder of colocynth was sometimes used externally, with aloes, etc., in unguents, bandages, etc., with remarkable success against parasitic worms; some, for the same purpose, recommended that the pulp be used as an enema. In iliac passion, enemas of colocynth were used effectively where most other premodern medicines had failed. Troches, or lozenges, made of colocynth were called “troches of alhandal“. They were prepared by cutting the colocynth to a small size, and reducing it to a fine powder in a mortar, rubbed with oil of sweet almonds; adding gum tragacanth, and mastic afterwards. Remedies for counteracting colocynth have included emetics, such as zinc sulfate, and apomorphine, if caught early; later, demulcents and opiates, with stimulants to combat collapse were used (Davis and Company Parke, 1909).
Nutritional uses
The desert Bedouin are said to make a type of bread from the ground seeds. Some confusion exists between this species and the closely related watermelon (Citrullus ianatus (Thunb)), whose seeds may be used in much the same way. In particular, the name “egusi” may refer to either or both plants (or more generically to other cucurbits) in their capacity as seed crops, or to a soup made from these seeds and popular in West Africa.
The seed flour is rich in micronutrients (vitamins and minerals), and could therefore be used in food formulations especially in regions with low milk consumption such as West Africa. A normal dose of fluid extracted from the fruit pulp is 2 to 5 minims (120 to 310 µl), and for the powdered extract 1 to 2 grains (60 to 130 mg) (Davis and Company Parke, 1909).
Practical uses
Since colocynth is not strongly used as staple food, its seeds might become an interesting source for biofuel production (Citrullus colocynthis, 2012). In addition, colocynth can grow on marginal lands and may improve soil quality as experienced with intercropping. The oil obtained from the seeds (47%) can also be used for medicinal and soap production. The production is not very time- and energy-consuming due to the ability of colocynth to grow on poor soils with just a little moisture and organic fertilizer. The fruits are harvested still unripe by hand, the rind is removed by peeling and the inner pulp filled with seeds is dried in the sun or in ovens. The seeds yield is about 6.7-10 t/ha, which means that for an oil profit of 31-47%, oil yields may reach up to 3 t/ha (Giwa and Solomon, et al., 2010).
