3.1       Source of Samples
The soybean seed was obtained from Kpiri-Kpriri market Abakaliki,
Ebonyi State, Nigeria.
Sample preparation
Soybean oil was extracted from the soybean seed as follows. The seed was cracked, adjusted for moisture content heated to 600- 88°C (140- I 900F), grinded and solvent extracted using hexane.

The tallow was obtained from Fulani herds men, at Amike-Aba Community in Abakaliki, Local Government Area of Ebonyi State, Nigeria
and was extracted from cow tissue.
They following analysis was carried out for comparative evaluation
of the two (2) products, soybean oil and tallow.

Soaking (use of hexane) for 48 hours
Soybean oil                                                                     Flow chart of soybean oil production

Size reduction
Soaking (use of hexane) for 48 hours
Tallow oil
                      Flow chart of tallow oil production

Peroxide value was determined by the method describe by (Onwuka, 2005). About 1g of oil sample was weighed into a clean dry boiling tube and 1g of powdered potassium iodine and 20ml of solvent mixture (20vol glacial+ 1vol chloroform) was added. The tube was placed in water bath set at
100°C and allowed to boil vigorously for 30 minutes.
In continuation, the mixture was transferred to titrating flask containing 2Oml of potassium iodine solution (5%) and the flask was washed twice with 25m1 of water and added into the titrating flask. The mixture was titrated with 0.002M sodium thiosulphate solution using starch as indicator. The blank will also be performed at the same time.
Peroxide value (meq/kg) 2v
Where v         =          volume of Na2So3 use during titration (ml).
The method describe by Morris (1999) was used for the determination. Precisely 0.5g of oil sample was weigh into a glass stopper bottle of 250ml, exactly 15m1 of chloroform and 25ml of wiji’s iodine solution was added with the aid of pipette. The mixture was placed in the dark for 30minutes.At the end of the period 2Oml of 15% potassium iodide solution was added and shaken thoroughly. The side of the bottle was washed down with 100ml of distilled water. The mixture was titrated with standard O.1N sodium thiosulphate solution of which the was added with constant shaking until the yellow colour of iodine almost disappears. Then 2m1 of 1% starch solution was added and the titration was continued until the blue black coloration disappears. Blank determination on an equal portion of the Wiji’s reagent was also carried out which pipette will be also allowed to drain for the same length of time.
Iodine value +          (b-a) x 1.269
Where a volume of the standard thiosulphate solution used for the sample
B         =          volume of the standard sodium thiosulphate used for the blank(ml)

W        =          weight of sample (g)

3.4       SMOKE POINT
The method described by Onwuka (2005) was adopted. About 20g of oil was poured into evaporating dish with a thermometer suspended at the centre of the dish, ensuring that the bulb just dipped inside the oil without touching the bottom of the dish. The dish was placed on a stove and gradually, the temperature of the oil was raised. The temperature at which the oil sample was given off a thin bluish smoke continuously was noted as the smoke point in oC.
The method described by Onwuka (2005) was used for the determination, exactly 25m1 of diethylether, 25ml of alcohol and 1ml of phenolpthalein solution (1%) was mixed together and carefully neutralized with 0.lrn NaOh by titration. In continuation 1g of the oil was weigh in a conical flask and neutralized solvent was added to the sample and then titrated with 0.lm NaoH solution shaking constantly until a pink colour persisted for 15 seconds was obtained, % FFA (Expressed a palmitic acid) will be calculated as follows:
FFA (%) =    V x 0.0282  
Where, V = volume of NaoH used during titration (ml)
W =     Weight of sample (g).
The method described by Ishiwu et al Iwuno 2006 was used for the
determination. Empty pyknometer bottle was weighed and recorded its weight (w1), and the dry pyknometer bottle was fill with oil sample. When the temperature has reached the ambient temperature at which the measurement was made, the volume of the oil was made, the volume of the oil was adjust to a fixed mark or density bottle was use, care was taken to insert the stopper in such a way that the capillary portion was completely filed with the oil. Which was weigh and record the weight (w2).

Density - w2 - w1
Where V1 = volume of oil in pyknometer or density bottle in ml at temperature t°c.
The method described by lshiwu et al Iwouno (2006) was adopted.
About 2g of oil was weigh into a conical flask to within 0.001g and add
exactly 25ml of 0.5N ethanolic KOH solution. The flask was attach to the condenser. Boil gently, mixing from time to time. And heating stopped after 6Ominutes. 4-5 drops of phenolphthalein solution was added. And titrate the hot soap solution with O.5N hydrochloric acid solution.


Saponification value 56.1 x N x (‘B-S)
B         =         ml of hydrochloric acid solution used in blank test
S          =          ml of hydrochloric acid solution used for the sample
N         =          exact normally of the hydrochloric acid solution
W        =          weight in g of sample
The method described by Karl Fischer was used for the determination. Water was extracted from the oil sample into methanol and titrate with Karl Fischer reagent (Pyridine. iodine in anhydrous methanol) and the end point of the titration was detected visually or electrometrically.

The composition of oil extracted from fatty tissue and soybean seed are presented in table four below.
TABLE 4-: Chemical composition of extracted oil from fatty tissue (from cow) and soybean seed.
PV (Meq/kg)
Moisture content
Soybean oil

The value are means of tiplicate analyses
4.1 FREE FATTY ACID - The free fatty acids are the acids in oil which not esterified with glycerol to form glycerides, it is a relative measure of Rancidity of oil. From table 4a the mean values obtained showed that the free fatty acid recorded for tallow and soybean oil were 5.08% and 2.54% respectively. This result shows that tallow recorded the highest free fatty acid (5.08%) while the soybean oil had the lowest free fatty acid (2.54%). Since hydrolysis that may occur in the presence of moisture, this reaction is catalysed by some enzymes, acid bases and heat as reported Ihuria and Maliki (2007), the high value of tallows may be as a result of hydrolysis that occurred in the oil while less value of  free fatty acid in soybean oil could be due to reduced hydrolytic activities. Free fatty acid is important in determining the suitability of oil as edible oil, when the free fatty acid of oil is lower, more appeal the oil is for consumer as reported by Coenen (1976). The result showed that there are significant differences at (P< 0.05).
4.2 IODINE VALUE-: The Iodine value is a measure of fat stability and resistance to oxidation, iodine is a measure of proportion of unsaturated fatty acid present in given oil/ fat. Higher iodine value is attributed to high degree of unstauration in the oil/ fat as reported by potter and Hotchkiss (1995) table 4. Revealed that the iodine value of the samples tallow and soybean oil, were 70.24 and 84.35 respectively it can be observed from the same table 4 that the iodine value was affected by the  source of the material/ oil used, as reported by Fokou et al(2009). It was observed that soybean oil had the highest iodine value (84.35) there was significant difference at (P< 0.05)The iodine value that was obtained from soybean oil are less compared to the value reported by Ihekoronye et al (1985). Therefore the lower in the value may be due to freshly of the oil; while tallow oil had the highest iodine value than it’s stated by Ihekoronye and Ngoddy (1985) that animal fatty are majorlly inoleic in nature and most of the tallow oil depend on the specie of animal and its feed procedure since oxygen uptake (oxidation) of unsaturated fatty acid in phospholipids occurs readily and isomerization process usually lead to loss of unsaturation Ihuoria and Maliki (2007) than low iodine value of oil could be beneficial  since it is always associated with good quality and a longer shelf life of oil as reported by Ortega-nieblas etal (2007) and it prevent oxidative deterioration in food the result obtained showed that these was  significant different at (P< 0.05).
4.3 SAPONIFICATION VALUE-: Saponification value of oil is inversely proportional to the mean molecular weight of the glycerides in the oil. Saponification value is expressed as the number of milligrams of potassium hydroxides required to saponify one gram of fat/oil.
Saponification value of the sample is presented in table 4. The result shows that specification value of tallow and soybean oil were 185.58 and 291.17 mg/koH/g respectively the soybean oil had the highest value (291.17). While tallow oil had the lower value (185.58). The values obtained for tallow and soybean oil indicate that the free fatty acids presents in the oil have high molecular weight. This implies that soybean oil after hydrogenation could be substitute for the conventional oil in soap making and shampoo industry like other oil (Akintayo and Bayer 2002, Falade et al, 2008). This value actually measures the amount of alkali which is required to compare with the fatty acids liberated by the equivalent weight of the fatty acids  can be determined (Chamble and Harvey 1994). The soybean oil is made-up of short chain saturated fatty acids,. This is supported by the fact that the oil remained liquid at room temperature (28oC-300C) while tallow oil remained solid at room temperature and thereby being  made-up of long chain unsaturated fatty acids. The saponificatuion value of tallow oil are almost comparable with saponification value range of canarium schwnifurchii of African blank olive oil which was ranged from mesocarp and endocarp and it is commonly used as cooking oil by native people of Congo and Gabon (Abayeh et al 1999).
4.4 PEROXIDE VALUE (PV)-: Peroxide value is usually used as indicator of detecting deterioration of fat and oil, thereby oxidation takes place, double bonds in the unsaturated fatty acid are attacked forming peroxide which further breakdown to produce secondary oxidation products that may lead to off flavour and off dour in oil and fat (Ihekoronye and Mgoddy, 1985) peroxide values of the sample tallow oil and soybean oil are presented in table 4 above. The result show that the peroxide value of tallow and soybean oil were 27.33 and 52.00 meg/kg. The  peroxide value of soybean oil had the highest value (52.00 Meq/Kg) while the tallow oil had the lower value (27.33 Meq/kg). The different in the peroxide value may possibly depend on the varieties/ variation of the species of oil as the low peroxide value, indicate slow oxidation of this oil.
According to Decmian (1990) the peroxide value is frequently used to measure the deterioration of fat and oils. Therefore the low peroxide value obtained for tallow oil showed period fort lasting of the oil/shelflife of the oil before deterioration generally. Oils with peroxide value less than 30 Meq/kg have been considered safe for human consumption (Gotoh and Wada, 2006) while the soybean oil and tallow oil had higher values compare to the reported by Wada and Gotoh and the do not have good oxidative stability, the sample had their significant difference at (P< 0.05)
4.5 SPECIFIC GRAVITY-:The specific gravity of the sample tallow and soybean oil is shown in table 4 from the table the specific gravity of the sample were 0.879 and 0.9662 for tallow and soybean oil respectively,. The results obtain show that the soybean oil had higher specific gravity value of 0.9662. While the sample tallow oil had the lower specific gravity value of 0.879. It was observed that the result of the specific gravity of both tallow and soybean are low compare to the specific gravity value reported by Singh and Singh (2010), but the values are within the range reported by Onyeka et al (2005). The variation observed from the specific gravity result could be because of the significant difference in their saponification value) Molecular weight and degree of unsaturation) (Iodine value ) Onyeka et al (2005) also reported that the density of an oil increases with increase in their  saponification value iodine temperature free fatty acid and the water content the result obtained showed that there are significant difference at (p<0.05)
4.6       SMOKE POINT – Smoke Point  is one of the factors used in selection of oil for deep frying application German and Sherrington (1977) from the results presented in table 4, it was observed that the smoke point of fallow and soybean oil were from 2400C and 2800C respectively. The observation showed that the tallow oil had the highest smoke point value 280oC while the soybean oil had the lower smoke point value 2400C. The soybean oil had the smoke point that fall within the recommended smoking point for a good quality palm oil as reported by Onwuka (2005) while the tallow oil were not within the recommended range. This suggested that soybean oil and tallow  that had high value compare to other are not good mostly for deep frying processes.
            The result obtained show that there are significant difference at (p<0.05)
4.7       MOISTURE CONTENT: The moisture content of any food is an index of it water activity (aw) as reported by Fraizier and Wertoll (1978) from the result presented in table 4 moisture content values were 2.00 and 2.03 for tallow and soybean oil respectively. It was observed that their had the same ranged of result value. This implies that the value are good to prolong the shelf life of the oil due to their low moisture content that cannot make the to be oxidize when react.

            The soybean oil and tallow after extraction using n-hexane as solvent for oil extraction. The result obtained showed that physio-chemical properties of both oil are not the same. The result also showed that soybean oil are from plant source and in ambient temperature they are liquid and are better than other oil while the tallow  are solid at ambient temperature and had mostly higher chemical properties but when refined well it may serve as a good source of material to be used in production of different food.

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