Thesis Abstract

<p> The research project studies the analysis of pear and its oil. The mesocarp from<br>edible African pear “DacryodesEdulis” were evaluated for their oil yield. The<br>pulp from this pear were oven dried at 100oC-105oC to a moisture content level<br>of 29%.The mesocarp was subjected to proximate analysis to determine the<br>percentage of the moisture, ash, fat, crude fibre, crude protein and carbohydrate<br>content which resulted to the values of 29%, 2%, 19.6%, 25.5%, 11.9%, and<br>12% respectively. Then the dried sample was pulverized by using hammer mill<br>and the oil was extracted by solvent extraction using n-hexane. The oil extracted<br>were analyzed for the chemical properties i.e. (Acid value, saponification value,<br>peroxide value, iodine value) etc. the values obtained are respectively<br>8.41gm/KOH/gm, 185.1gm/KOH/gm, 2.8gm/KOH/gm 3.96gm/iodine/gm and<br>Physical properties i.e. (Refractive index, Ph value, specific gravity) which the<br>values obtained are 1.469brix, 5.7 and 0.92. and the The percentage oil yield<br>content is 51.57%. This physio-chemical characteristic and fatty acid<br>composition of this oil show that they have industrial potentials. <br></p>

Thesis Overview

<p> </p><p>1.0 INTRODUCTION<br>In the major world, one major source of protein and vegetable oil is from<br>oil seeds /fruits (Williams M. A. 1996). Oil constitutes a well defined class of<br>naturally occurring substance. It is greasy, being soluble in organic solvents but<br>insoluble in polar solvents such as water. Oil is a liquid at room temperature.<br>Commercially, oil as well as fats is sourced from certain plant groups mostly<br>seeds and nuts and some parts of animal within which they occur in relatively<br>large quantity in an easily available form (McGraw-Hill, 1997). The existence<br>of oil in certain plants has been known for century of years (Ogbu 2005).Oil can<br>be grouped into edible and non-edible oil depending on the amount of<br>unsaponified matters and impurities contained therein. Edible oil extracted from<br>African pear, bread fruits, cashew nut, peanut etc. are examples of vegetable oil<br>which are naturally occurring esters of higher fatty acids and glycerol, and are<br>predominantly triglycerides with traces of mono and diglycerides, sterples, antioxidants,<br>vitamins, saturated and unsaturated free fatty acids and other minor<br>constituents. They are widely distributed in nature and were first consumed as<br>food. Later, oils were discovered to be used as renewable raw materials for<br>variety of non-food production. For instance; soaps, creams, disinfectants,<br>paints, enamels, inks etc.<br>2<br>Due to the oil boom in the early 70‟s, agriculture was abandoned for petroleum<br>and its product, but recently, things are taking a new turn in Nigeria over<br>dependence on petroleum for virtually everything has not really helped matters.<br>The economic situation in the country is bad and the general standard of living<br>is getting poorer with each passing day, Hence, the need for a restructure of the<br>economic system with an agricultural bias.<br>Most agriculture products such as these oils extracted from local seeds and nut,<br>if properly monitored and harvested can be very useful for us down here and<br>even exported for foreign exchange, hence the need for this project which deals<br>on the extraction and analysis of African pear oil.<br>Extraction of oil from various vegetable resources is of ancient origin. In fact,<br>the natives from different tropical regions of the globe have long been<br>extracting oil from numerous oil-bearing plants. Humans, since the ancient<br>times have known how to extract fats and oil from their natural resources.<br>Historically, oils had been extracted by wrapping nuts in clothes and then using<br>devices operated by stones and levers to exert pressure on them. But now, an<br>improved form of mechanical device, which allowed considerably more<br>pressure to be exerted, is now in use in form of hydraulic operated ram. This<br>type of press is developed into a motorized hydraulic pump system that pressed<br>the nut bag and then released a pressed cake. The next improvement in<br>extracting oil is the screw press or expeller which is been driven by electric<br>3<br>motor.Because most press or expeller processes leads to over-heating of the<br>meal and leave too- much of the high value oil in cakes, better methods of<br>extracting the oil with solvent was developed. Bush pear was processed by<br>solvent methods alone in this project. This process can be accomplished by a<br>variety of ways but as might be expected, its efficiency depends to a great<br>extent on attaining intimate contact between the liquid solvent and the solid<br>containing the solute. The type of solvent available for this process include nhexane,<br>petroleum ether, benzene, n-heptanes, acetone etc.<br>1.1 HISTORICAL BACKGROUND OF THE STUDY<br>The generic name “Dacryodes” was derived from the Greek word “Dakruon”<br>meaning [tear] referring to resin droplets on the bank surface of its member<br>while “Edulis” means edible emphasizing the importance of nutrients fruits in<br>the plants cultivation .The plant belongs to the family Burseraceae whose<br>members are characterized by an ovary of 2to 5 cells, prominent as inducts in<br>the bark, wood, and intrasteminal disk (Chunduff, 1984). The genus Dacryodes<br>consist of about 10 species (Verheji, 2002). However (Rehn, 1984) indicated 80<br>species to encompass sub species of varieties, form and cultivars. Two varieties<br>are recognized; Var-parvicarpa and Var-edulis whose conical fruit is smaller<br>with the pulp. Var-edulis exhibit verticulate or sub-verticulate branching while<br>the branching is slender and opposite or bifurcate in var-parvicarpa (Okafor et.al<br>1983).<br>Dacryodesedulis is an indigenous fruit in the Gulf of Guinea and central<br>African countries(Troupin, 1950), but due to the popularity of the nutritious<br>fruit for consumption, the plant is widely cultivated, extend its area of<br>distribution to Sierra-Leone, Uganda, Angola, Zimbabwe and Nigeria. It rarely<br>grows wild, thus the natural area of distribution is obscure (verheji,2002). Lam<br>gave four synonyms viz to the Dacryodesedulis :CarnaruimedulieHook.f,<br>CarnaruimsaphuEngl, Pachylobusedulis (G.don) Hook. F. and<br>PachylobussaphuEngl (Burkill ,1985,National research council,1996).<br>However, these synonyms have long been considered as the most unambiguous<br>synonyms (Boutelje,1980).The common names are in English, African pear,<br>African pear tree, Bush butter, Bush butter tree, Bush fruit tree, Eben tree,<br>Native pear (Kapseu and Tchiegang, 1996) and in French, Safoutier (Burkill,<br>1985). The oil of fruits of DacryodesEdulis is a rich source of amino acids and<br>triglycerides. The fatty acid composition of fruit pulp oil of two cultivars of<br>bush pear [cultivar1 and cultivar2] grown in Nigeria were determined. The oil is<br>found in the pulp which is made up of 48% of oil and a plantation can produce<br>7.8 tons of oil per hectare. It is also rich in vitamins and a rich source of amino<br>acids triglycerides (Derbyshire.et al 1976).<br>Bush pear oil is one of the most important rated versatile vegetable oil. This is<br>due to its uses in various spheres of life, most especially as a very healthy food<br>ingredient.<br>1.2 AIMS AND OBJECTIVES<br>This project is aimed at the analysis of bush pear and its oil.The main objective<br>of this study is to carry out proximate analysis and physio-chemical properties<br>of African pear oil extracted by solvent methods. This physio-chemical<br>properties determined are specific gravity, refractive index, ph value, boiling<br>point, acid value, iodine value, peroxide value, and saponification value. To<br>achieve the objectives of this project, it is important to:-<br>a) Select the best suited solvent for optimum yield.<br>b) Characterize the extracted oil for compositions and properties.<br>c) Test the suitability of the oil.<br>1.3 STATEMENT OF THE PROBLEM<br>This research work involves the analysis of African pear and its oil though the<br>food crop African pear potential is rated one of the highest oil producing fruit<br>crop yet it begs the question of its potential.<br>Furthermore, this project will answer the following questions;<br>i) Solvent extraction by solvent method<br>ii) What is the optimum yield of the particle size using n- hexane?<br>iii) Is there significant difference in the characterization of the extracted oil as<br>compared to theoretical value in terms of;<br>1) Chemical properties (Acid value, iodine value, saponification value and<br>peroxide value).<br>2) Physical properties (specific gravity, density, viscosity, refractive index).<br>3) Chemical composition (protein crude, fibre, carbohydrate and moisture.<br>1.4 SIGNIFICANCE/ECONOMIC IMPORTANCE OF THE STUDY<br>Characterizing the potentials of African pear/African pear oil for many<br>purposes has several implications. Communities in the West African countries<br>are significantly dependent on financial gain from agrarian enterprise.</p><div><div></div></div><br> <br><p></p>