African bread fruit (Treculia African Decne) is a member of the maraca family. The seed s are highly nutrition and constitute a source  of vitamins, minerals protein, carbohydrate and fat (Okafe and Okow 1994, make ride and Elema, 1985). Bread fruit seeds are generally consumed in the entire South Eastern Nigeria and beyond. They can be consumed in various form; cooked as porridge or roasted and eaten with palm kernels (Edet et al 1985). African bread fruit has a limited shelf life period due to its  high moisture and fat content (Okafor 1990). Oknokwo and Ubani (2012) reported that African breadfruit seeds can preserved by sundrying of the dehulled seeds.

Dehydration operations are important steps in the chemical and food processing industries. The basic objective in drying food products is the removal of water in the solids up to a certain level, at which microbial spoilage is minimized (Krokida and Marinoskouris, 2003). Further research has shown that on the local level, some people dry breadfruit seeds using not only sun drying but also shade drying to extrend the shelf life of the product (personal communication, 2013) this has resulted in products of various qualities and there is a need to study the effect of these different drying methods on not only the sensory quality but also the physical properties and proximate composition of the seeds.  Jokic et al (2009) reported that the changes in quality that can occur in any part product during drying are those on its optical properties (colour, appearance), sensory properties (odour, tase, flour), and structural properties (density, porosity, specific volume, textural properties, etc).
            The knowledge of the influence of drying on the food properties can be efficiently used to create new quality attributes and new functionalities for the final products (Lewicki 2006). Also, the knowledge of the physical properties o the dehydrated African breadfruit seeds like those of other seeds is essential for the design and construction o equipment systems, handling storage and preparation as they affect food quality and acceptability (Onwuka 2005).
1.1       OBJECTIVES
The objectives of this work are:
1.         To dry African breadfruit seeds using three different methods namely sun drying, oven drying and shade drying.
2.         To determine the effect of these drying methods on the physical, proximate and sensory properties of the seeds.

2.0                                                                               LITERATURE REVIEW
            African breadfruit (Treculia Africana) is a multipurpose tree species which belongs to the family moraceae and it grows in the forest zone. Particularly the coastal swamp zone (Agbogidi and Onomaregbo, 2008). It is widely grown in Southern Nigeria for its seeds, and is known by various tribal names in the country. Such names include “afon” (Yoruba), “Barafuta” (Hausa), “Ize” (Bini), “eyo” (Igala), “ediang” (efik) and “ukwa” (igbo). (Iruine, 1981; Onweluzo and odume, 2008). The most popular of these tribal names is the igbo tribal name which is “ukwa” the specie is a large tree which grows up to 30m high and it flowers between October and February (Salami, 2002).
            According to Okafor (1985), there are three varieties of African breadfruit, these include var. Africana, var mollis and var. inverse. These are distinguished based on the size of the fruit heads and hairiness of the branches and leaves. Beside varieties, Africana and inverse thrive well in a wide range of soil from sandy to clay soil and require high rainfall and humidity as well as ample sunlight. Propagation is by see, stem and budding which has helped production f the maturing tree fruit in about 2-4yers, opening up the flood gate for mass production of breadfruit and as a result the need form an enhanced utilization of African breadfruit to match the production.
            In addition, African breadfruit variety rates higher both in yield and nutrition.

2.1.1   Description of African Breadfruit Plant
            African breadfruit is a large tree growing up to 30m high with a girth of 4.6m. It has a dense spreading crown and fluted trunk. The bark is grey, smmoth and thick exuding capious cram latex which later turns rusty red when cut (Agbogidi and Onomeregbor, 2008). The leaves are simple, alternate, very large, dark green, smooth above, tough and paler bwlow with some hours on the 10th-18th pains of clear reins with painted tips and short stalk (WAC, 2004). African breadfruit is a monvecious dictyledonous plant with flowers crowded into compact heads. The flowers of the both sexes are surrounded by specialized bracts between which stamen or stigmas project above the surface of the flower head (Ugwuoke et al, 2003). The fruit is round in shape, big, greenish yellow in colour and spongy in texture when ripe and contains numerous seeds, which are embedded at various depths in the fleshy pulp (Enibe, 2007). The seeds are brown in colour with fibrous coating (Okafor, 1990).
2.1.2   Utilization of African Breadfruit
            African breadfruit is a traditionally important edible fruit in Nigeria (Okafor, 1985) whose importance is due to the potential use of its seeds leaves, timber, roots and bark. It is increasingly becoming commercially important in Southern Nigeria hence, Baiyeri and Mbah (2006) described it as an important natural resource which contributes significantly to income and dietary intake of the poor. African breadfruit could be processed and utilized in variety of ways. The seeds are used for cooking and are highly nutritious as pointed out by various authors (Okafor and Okolo, 1974; Okafor, 1990; Onyekwelu and Fayose, 2007). The seeds are variously cooked as pottage or roasted and eaten with palm kernel as read side snacks. Apart form being consumed as a main dish, the seeds are also processed into flour which has high potential usage for pastries (Keay, 1989).
            The seeds are also used as flavouring in alcoholic drinks and edible oil can be processed form the seeds (Irvine, 1981; Ugwuoke et al; 2003). Ejiofor et al; (1988) prepared a non-alcoholic beverage form seeds of the species which was found acceptable when taken without milk and sugar therefore, giving the beverage obtained from the specie an obvious advantage over cocoa-derived beverage in view of the scarcity and expensiveness of milk and sugar in rural areas of developing countries. The wood is suitable for firewood and charcoal production (Field survey, 2008).
            The breadfruit oil could be used for cooking, preparation of soaps in the pharmaceuticals, production of hair shampoo, alkyl resin used in paints and varnish industries due to the drying nature of African breadfruit oil with its high oil yield (AJiwe et al; 1995). The bran and pulp of Arican breadfruit have been found to be nutritious for use in live stock feeds (Okafor, 1090). The roots are used as a malaria tonic and worm expeller for children while the bark is used as treatment for cough neck swelling and rheumatism (Irvine, 1981).
2.1.3   Limitation in Breadfruit Utilization
            There are various factors that limit the use of breadfruit when it is compared to other plants like legumes since it has same functions with breadfruit these include:
i.          The long period of maturity and fruiting which makes it seasonal fruit.
ii.         The long cooking time, which is associated with hard-to-cook phenomenon which has contributed greatly to the low consumption in the urban dwellers whose cooking time are limited, as such a rich and equally cheap source of dietary protein is neglected.
iii.       The ability to produce gas in the gastro intestinal tract, which is referred to as flatulence.
iv.        The limited shelf life period during due to high moisture and fat content (Okafor, 1990).

2.1.4   Nutritional value of African Breadfruit
The African breadfruit produced by Treculia a wild tropical evergreen tree and has immense potential as a nutritional sources for man (Osabord et al; 2009).
Like most grain legumes cultivated in Africa, African breadfruit is a source of protein, fat, vitamin, mineral etc. African breadfruit like other grain legume is rich in protein than that for cereals and similar to most pulses and is also particularly high in aromatic amino acids which makes it a potential source of good quality protein (Makinde et al, 1985). It is also rich in carbohydrate due to its high carbohydrate contents and could therefore serve as a good source of energy. African breadfruit seeds contain less fat than some other nuts and about 4-7% total lipid content (Nwaokorie, 1983). It is therefore recommended, as part of weight reducing diet the seeds are low in crude fibre and also not a good source of dietary fibre, which is important for reducing cholesterol levels in the body to minimize risk of cardiovascular disease caused by high plasma cholesterol (Umoh, 1998). It is also a good source of vitamins like beta-carotene, vitamin C and folic acid (folate).
African breadfruit is rich in some minerals notably magnesium, potassium, and calcium but poor in sodium, iron and copper as reported in literature (Oyenugo, 1968; Edet, 1982; Ejidike and Ajileye, 2007). They therefore need to be fortified with sodium, iron and copper when used in food formulations because of their low inherent levels. African breadfruit seeds are also rich in flavonoids, polyphenols, cardiac glycoside saponins and authraguinones, which are known to have antimicrobial activity (Sofowora, 1980). The presence of these secondary metabolites accounts for the usefulness of the seed medical purposes (Ebena et al, 1995).
            Preservation of food by drying is a common practice in different parts of the world and it is used to extend the shelf life of food. Drying allows food to be preserved by removing te moisture in the food in order to prevent the growth of microorganisms that cause deterioration (Mukhtar, 2009). Since drying removes the water from the food, the weight of the food items also reduces. This not only makes it lighter but also shrinks it in size thereby making it easy to store and sorry. Dried food requiring no refrigeration makes it ideal for domestic use as well as for use in the rough outdoors.
            Drying food is simple, safe and easy to learn. Dried foods are good source of quick energy and whole some nutrition, since they only thing lost during preservation is moisture (, 2013). Dried foods are on easy option for busy executives, active women and children, all of whom can benefit form the case and nutritional content of dried foods.
            There are several ways of drying food which include: In the sun, in on oven, in the shade, in the room or in a commercial dehydrator.
2.2.1   Sun Drying
            There are many techniques of drying but the cheapest and most commonly used in Nigeria is sun-drying. The method however, results in contamination with dust and microorganisms and is sometimes too slow to accomplish the desired purpose especially in wet weather (Adom et al; 1997). Sun drying is also a cheap process and the dried foods have more monetary value when compared to dehydrated food due to improved quality. Sun drying has advantages but not on the basis of time to dry and quality (Desrosier; 1970).
2.2.2   Oven Drying
            An oven can easily and effectively be used to dry food ovens have all the three elements needed for food drying-had, low humidly, and air flow. Drying food in the oven is a slow and time consuming process. Most ovens do not have an in-built fan and therefore they end up taking more time and energy to dry relatively small quantity of food ( 2013).
2.2.3   Shade Drying
            Shade drying is a drying technique which requires full air circulation. It should not be undertaken inside convectional buildings but in on open-sided shed purposely built for shade drying. Shade drying takes a little longer than sun-drying but it prevents the loss of a foods natural colour and better preserves its vitamins and minerals ( 2013)

2.2.4   Room Drying
            Drying food in the room is different form sun drying. Here, the food that has to be dried is placed in a well ventilated room or covered space ( 2013).
2.2.5                               Effects of Different Drying methods on Food
            Loss of nutrients has been reported for various food processing techniques (Brar et al, 2006; Uhling, 1998; Svanberg and Nyman, 1997). Sun oven and solar drying methods utilize heat to remove water from food by evaporation. The removal of water by heat has been reported to effect the nutrient contents of food in various ways. It can either increase the concentration of some nutrients 1g making them more available or decrease the concentration of some nutrients (Hassan et al, 2007); Morris et al, 2004; Ladan et al, 1997). Application of heat can be both beneficial and detrimental to nutrients. Heat improves digestibility of food, promotes palatability and also improves the keeping quality of food, making them safe to eat. Heating process also result in nutritional losses by inducing biochemical and nutritional variation in food composition.
            According to Rozis et al (1997), vitamin losses are often greater during peeling than during drying. Loss of far soluble vitamins can also be reduced by shade drying and loss of eater soluble vitamins by careful slicing using sharp knives. Ascorbic acid and carotene are subject to damage by oxidative processes. Riboflavin is light sensitive whereby Thiamin is heat sensitive and destroyed by sulfuring (Desiosier, 1970). Sun drying causes large loses in carotene content. The retention of vitamins in dehydrated foods is generally superior in all counts than in sun-dried foods.
            In drying, a food loses its moisture content which results in increasing the concentration of nutrients in the remaining mass. Proteins, fats and carbohydrates are present in large amounts per unit weight in dried foods than in their fresh counter part. The biological value of dried protein is dependent on the method of drying. Prolonged exposures to high temperatures can render the protein less useful in the dietary. Low temperature treatments of protein may increase the digestibility of protein. Over native material (Desrosier, 1970).
            Rancidity is an important problem in dried foods. The oxidation of fats in food is greater at higher temperatures than at low temperatures of dehydration. Fruits are generally rich sources of carbohydrates, poor sources of protein and fats the principal determination in fruits is in carbohydrates. Discoloration may be due to enzymatic browning or to carmelization types of reaction. Slow sun drying permits extensive deterioration unless the tissues are protected with sulfites or other suitable agents. Animal tissues do not contain large amount of carbohydrate and therefore their carbohydrate deteriorations are of minor importance.

            Physical properties of food are those properties which are used in process design, product and process optimization, product development, food quality control and food process modeling, (Salin and Gulum summnu, 2006). Physical properties of agricultural materials affect how they are to be processed, handled, stored and consumed and so are required in the design of planting, harvesting and post-harvest operations such as cleaning, conveying and storage (Mosoumi and Tabill, 2003: Kotwaliwale et al, 2004; Wilheim et al; 2004). Processing techniques and handling of legumes require accurate knowledge of the physical properties such as shape, size, porosity, surface area, bulk density (Alobadan, 1996).
2.3.1   Porosity
            The porosity is the fraction of the space in the bulk seeds which is not occupied by the seeds (Coskiner and Karababa, 2007). Porosity also depends on geometry and surface properties of the material. The percent void of an unconsolidated mass of material such as grain, hay and other porous  materials are often needed in air flow and heat studies (Mohsenis, 1986). This property allows fluid to pass through the bulk, it is useful in the calculation of rate of aeration and cooling, drying and heating and the design of heat exchangers and other similar equipment (Asoegwu et al., 2006).
2.3.2   Density
            Bulk density is the mass of a material per unit volume. It is the property that makes it possible to separate them form materials that are less dense than water (Sirisomboon et al., 2007); Pliestic et al, 2006; and Cevat & Ozcan, 2002). Decrease is bulk density is an indication reduced overall quality of grain. Factors which commonly affect bulk density are insect infestation, excessive foreign matter and high percentage moisture content (WFP, 2006).
            True density is also a property that makes it possible to separate them materials that are less dense that water. True density is a characteristic that can be used to design separation or cleaning process. According to Eke et al.; 2007, the three density indicates that African breadfruit seeds float water, whereas bambara seeds do not.
            Bulk density and porosity affect the structural loads and are important parameters in designing of drying and storing systems.
2.3.3   Sphericity
            Sphericity of the seeds indicate the ability of the seeds to roll. Bambara seed are more spherical and will roll rather than slide unlike African breadfruit seeds (Mporokwene et al., 2008). This property is useful in the design of hopper, chutes, storage facilities and dehilling equipments for seeds (Mporokeane et al., 2006).
2.3.4   Surface Area
            The surface area affects the velocity of air stream that can be used in order to separate seed from unwanted material in pneumatic separator no to sepank  seed in pneumatic conveying specific surface area is considered  during mass and energy transfer through the surface of seeds (Asoiro et al, 2011).
2.3.5   Size and Shape of Seeds 
            These properties are always considered when designing hoppers and dehulling equipment for seeds.

About 2kg of fresh seeds of African bread fruit (Treculia Africana) to be used for this work will be purchased from meat market in Abakaliki, Ebonyi State, Nigeria.
            The sample will be prepared by sorting of the African breadfruit to separate them form stones ano other unwanted seeds. This will be done by spreading the African breadfruit on a wide flat and clean surface screen.
3.2.1   Srying Treatment
            The     African breadfruit will be divided into four parts of 500g each. The first part will be dried in a hot air oven at a temperature of 50oc till dried. The second part will be dried under the sun. the third part will be dried indoors while the fourth part will not be dried and will sere as the control. The dried samples will be stored in labeled air tight polythene bags until needed for analysis.

            The following analysis will be carried out to determine the proximate composition of the fresh and dried samples respectively.
3.2.1   Determination of Moisture Content
            Moisture content of the sample will be determined according to the method described by AOAC (1990). Empty Petridis will be washed, dried in an oven and cooked in a dessicator. The dry clean dish will be weighed and recorded as w1, after which 5g of the sample will be introduced into the dish, weighed and recovered as w2. The dish + sample will be transferred into an oven at 1050c to dry for 2 hrs. A pair of tongs will used to transfer the dish into a dessicator, allowed to cool and weighed. The dish will be returned to the oven for 3o mins and again cooled in a desiccators and weighed. The procedure will be repeated until a constant weight is obtained and recorded as w3
(%) moisture =          w2 – w3  x  100
                                    w2 – w1        1
where w1        =          weight (g) of Petri dish
            w2        =          Weight (g) of Petri dish + sample before drying
            w3        =          Weight (g) of Petri dish + sample after drying
3.3.2   Determination of Ash Content
            The ash content will be determined as described by AOAC (1990). The empty crucible will be washed, dried and cooked in a dessicator. About two grammes of the sample will be weighed into a tared silica dish and the sample will be heated inside a fume cupboard until the smoke disappears. The sample will be transferred into a muffle furnaces at the temperature of 55ooc for 2 hrs until a white or light grey ash result when the residual is black in colour, it will be moistened with a small amount of water to dissolve salts. It will be cooled in a dessicator and re-weighed.
% Ash =                      w3 – w1 x  100
                                      w2 – w1   1
where w1        =          weight (g) of crucible
              w2      =          weight (g) of crucible + sample before ashing
              w3      =          weight (g) of crucible + sample after ashing

3.3.3   Determination of  Crude Protein
            Crude protein content will be determined by micro kjeidahl method (AOAC, 1990). A quantity of sample (0.5g) will be weighed into a 500ml kjeldahl flaks. Ten grammes (10g) of sodium sulphate (Na2so4) and lg of copper sulphate, followed by 20ml of H2so4 will be weighed into the flask too. The mixture will be digested under a fume cupboard until a clear solution is obtained. The digest will be cooled and 20oml of distilled water will be added followed by 6oml of 40% sodium hydroxide solution. The ammonia in the boric acid solution containing 0.5ml of indicator (screen methyl read. The distillate will be collected and titrated with 0.1 NHCL. The nitrogen content will be multiplied by 6.25 to obtain the protein content of African breadfruit and expressed as percentage on the weight basis.
% protein       =          Tv x 0.1N x 0.014 x 6.25  x  100
                                           weight of sample                1
where TV       =          Titre value
              N       =          Normality of HCL used
            6.25    =          Conversion factor of protein

3.3.4   Determination of Cruds Fat Content
            The crude fat will be determined using soxhlet apparatus with petroleum ether as solvent described by Onwuka 92005). Two hundred and fifty milliliters capacity boiling flask will be washed, dried in an oven and transferred into a dessicator and allowed to cool. Two grammes of the sample will be accurately weighed into a labeled thimble. Cooked boiling flask will be filled with 300ml of petroleum ether. The extraction thimble will plugged light with cotton wool. The soxhlet apparatus will be assembled and allowed to reflux for about 6 hours. The thimble will be removed with care and petroleum ether will be collected in the tap container of the set up and drained into a container for reuse. When the flask is almost free of petroleum ether, it will be removed and dried. It will be transferred form the oven into a dessicator and allowed to cool then weighed.
% fat               =          weight of fat              x          100
                                    weight of sample                     1

3.3.5   Crude Fibre Determination
            The crude fibre will be determined using the method described by Joslyn (1970). Two grammes of sample will be weighed into a thimble together with petroleum ether into the soxhlet extraction Apparatus. The operation will be corried out until fat is extracted. The dried residue will be boiled under reflux for 30 mins with 200ml of 1.25% H2so4, it will then be filtered. The residue will be boiled with 200ml of 1.25% HaoH in a round bottom flaks for another 3o mins. It will then be filtered with a filter paper in a butcher funnel. The crucible will be weighed and dried in the oven, cooled in the dessicator and weighed. It will then be incinerated in the muffle furnace at 600oc for 21/2 hours, cooled in a dessicartor and weighed. The loss in the weight will then be recorded as the crude fibre. Percentage crude fibre will be calculated as
Crude fibre(%)         =          weight of crude fibre      x  100
                                                Weight of sample used        1
3.3.6   Carbohydrate content Determination
            The carbohydrate content will be calculated by difference, 100-(% moisture + % fat + % protein + % crude fibre).

3.3.7   Determination of physical Properties
            the method stated by mpotokwone et al., (2008) will be adopted to measure the linear dimensions of the African Breadfruit. Hundred (100) whole seeds will be selected form each sample. The length (L), width (w), and the thickness (T) will be measured using a vernier caliper. The geometric mean diameter (Dg) and sphericity (CP) will be calculated using the following formula reported Mohcenin (1986).
Dg       =          (LWT)1/3
a         =          (LWT)1/3
Seed volume (c) and seed surface area (S) will be calculated using the formula reported by Jain and Bal (1997).
V         =          BeLe
S          =          BeLe
where B          =          (WT)0.5
Aspect ratio (AR) will be calculated using (Mohsenin, 1986; ciro: 1997).
AR      =          W
Thousand unit mass of seeds will be calculated using the formular reported by Asoiro et al (2011). The mass of one hundred seeds of each sample will be recoded using an electronic balance. 1000-unit mass will be calculated by multiplying the 100 units of the seeds by 10.
Bulk and seed Density
            The bulk density of the seeds will be calculated using the method of Asoewgu et al (2006) cited by Mpotokwae et al (2008). A 500ml cylinder will be filled to the 500ml mark with breadfruit seeds and weighed on an electric balance. The bulk density will be calculated as the ratio of bulk weight and volume of the cylinder (g/ml).
            The true density will be calculated using the liquid displacement method of Asoegwu et al. (2006). All weights will measured using a top loading balance. A 500ml beaker will be filled to the 350ml mark with water. Appproximately 100g of seed will be immersed in the water. The mass of the water displaced will be balance reading with the seed submerged minus the mass of the beaker will water. The seed volume will be estimated by dividing the mass of displaced water (g) by the density of water (glcm8). Seed density will be determined by dividing the seed mass by the measured seed volume. This was repeated thrice for each sample.
Seed Porosity
            Seed porosity is the property of the grain that depends on its bulk and kernel densities. The formula stated by Mpotokwane et al 92008) will be used to calculate the porosity.
P          =           1 –  Pb          x   100
Where Po = bulk density (kg/m3) and Pt = seed density (kg/m3).
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