1.1. BACKGROUND OF THE STUDY
There has been an increase in the world production of oilseeds over the last thirty years (Murphy, 1994); this would appear to be related to the increasing demand for oilseed products and by-products as oilseeds are primarily grown for their oil and meal.
Oils from most edible oilseeds are used in the food industry, though there is growing emphasis on industrial utilization as feedstock for several industries with about 80% of the world production of vegetable oils for human consumption. The remaining 20% utilization is between animal and chemical industries (Murphy, 1994).
According to Rajagopal et al. (2005), bio-oils from oilseeds are used as Straight Vegetable Oil (SVO) or as biodiesel (trans esterified oil) depending on type of engine and level of blend of the oil; scent bean oil i.e. Ozaki, Ijiliji, or Azamu is found mainly in the South-East of Nigeria and is not an exception. This phenomenon has created a school of thought that it is better to use oilseeds as bio-fuel, which will lessen the competition for fossil fuels, which are not renewable. Fossil fuels are not only costly in terms of price but are also costly to the environment as they degrade land, pollute water and cause a general destabilization of the ecosystem with global warming as an end result. Furthermore, crude oil wields socio-political power that often dictates the pace of economic growth in specific locations, especially non-oil producing nations.
Nevertheless, the petroleum industry requires a greater quantity of oil to meet its demand.
Demand, however, by the food industry alone is not secure for many developing countries like Ghana that depend on imports of vegetable oil and fossil fuels. In order to meet the required amounts needed by all industries, these fats and oils must be available in large quantities locally with an effective extraction process at an affordable cost. The ability of a particular oilseed to fit into the growing industries depends on its utilization potential, rate of production, availability and ease of the processing technology. Thus while some oilseeds are being largely utilized in the oil processing industries, quite a number of oilseeds are under-exploited.
Generally, oils and fats from seeds and nuts constitute an essential part of man’s diet. Fats and oils, together with proteins, carbohydrates, vitamins and minerals, are the main nutrients required by the human body. Fats and oils are rich sources of energy, containing two and a half times the calories of carbohydrates (per unit weight). In addition to being a source of vitamins A, D, E and K, fats and oils also contain essential fatty acids. These essential fatty acids are not manufactured by the body and must be obtained from diets, with linoleic, oleic and linoleic acids as examples of unsaturated fatty acids (NRI, 1995).
Modern processing of vegetable oils yields valuable products such as oleo chemicals. Oleo chemicals are now largely being used in the manufacture of many industrial products, namely building auxiliaries, candles, detergents and cleaning agents, cosmetics, fire-extinguishing agents, flotation agents, food emulsifiers, insecticides, lubricants, paints, paper, medicine and chemicals. The meal or cake is used in the formulation and preparation of livestock feeds and food additives.
The production of oil plants takes third place in the world production in terms of value, after starchy plants and fruits, and ahead of beverages and stimulants. Edible seeds and nuts noted for their oil contents include palm nut, coconut, soya bean, olive, groundnut, sunflower seed, and cottonseed, while non-edible seeds and nuts include jatropha seed, neem seed, and castor bean. Moreover, bean oil has strengthened its dominant role among fats and oils produced based on its quality and nutritional grade. Bean oil contains linoleic, oleic and linoleic acids that are found in many plant oils. Shortage of these fatty acids leads to deficiency symptoms especially in growing children and animals. Bean oil has the highest content of lecithin (1.1-3.2%) which is a surface-active compound used as an emulsifier in the food and pharmaceutical industries, and other industries (Sigmund and Gustav, 1991).
Among the industries that use oils and fats from oilseeds, apart from the food industry, are the beauty, pharmaceuticals, aromatherapies, building and construction, and the petroleum industry.
1.2. Problem Statement
Many plants have been identified as sources of oil, with some of the plant species and their oil extracted and used as medicines and food. However, very few of these species have their oil characteristics determined.
Because of the high demand of oils for various purposes including medicinal, perfumery, soap making, insecticides et al. Imported oils are very expensive to meet the demands of our local consumer industries; therefore, it becomes necessary to source and synthesize these oils locally. Since these oils can be produced locally, it gives no reason for their importation or at least should reduce the rate at which these oils are imported and give attention to local production.
1.3. OBJECTIVES OF THE STUDY
The purpose of this study is to
a. Find the percentage composition of oil in the bean seed
b. To determine the effect of particle size on the yield of the oil.
1.4. SIGNIFICANCE OF THE STUDY
Exploitation of fruits and seeds as a source of oil can help to reduce oil costs by diversifying the sources for this commodity. Data generated from this study will benefit industries for production of oils for various purposes.
In addition the content and composition of fatty acids of plant seed oils can serve as plants taxonomic markers.
1.5. JUSTIFICATION OF THE RESEARCH
Some factors and benefits of bean (“Ozaki, Ijiliji or Azamu”) oil make the research worthwhile;
1 The bean is readily available.
2 Oil from this particular bean is medicinal and applicable in pharmaceutical industries.
3 Small scale industries coming up as a result of oil extraction can reduce unemployment.
4 It can attract foreign exchange earnings for Nigeria.