3.1       Sources of Raw Materials
The palm fruits that were used for this work were purchased from Ikwo Local Market in Abakaliki, Ebonyi State. You can also find it in Imo State, Anambra State, Abia State, Enugu State in Eastern Nigeria.
3.2 Method of Preparation:
The fruit was divided into two equal parts and was processed into palm oil using two different traditional processing method (boiling processing method and fermentation processing methods).

3.2.1. Boiling Processing Method:
The first part of the palm fruit was washed, boiled for one hour and pounded using mortal and pestle until the tissue separated from the kernel. The pounded palm fruit was allowed to cool by addition of cold water so that during pressing, oil will flow on top of the water. Oil was collected by decantation to drain off water. The oil was then heated to remove the moisture present in the oil. Other unwanted impurities were scooped out. The resultant oil was allowed to cool, then transferred to a plastic container and stored at ambient temperature for a specified period of time. Samples were analyzed monthly for up to six months.
3.2.2 Fermentation Method
The second part of the palm fruits was kept in a sack, covered with plastic cover and allowed to ferment for a period of 10 days starting from the day the fruit was purchased. The palm fruit were watered everyday to keep them moist. After the 10days the fruits were pounded using mortal and pestle without cleaning off any moldy growth. The pounded palm fruit was kept till the following morning before extracting the oil. The extracted oil was heated to remove unwanted impurities and moisture. The resultant oil was transferred to a plastic container and stored at ambient temperature. The oil obtained was analyzed monthly for specific gravity, Acid value/ free fatty acid, Iodine value, saponification value, peroxide value, melting point, freezing point. 

3.3.1 Specific Gravity Determination
The method described by Onwuka (2005) was employed. Pynometer bottles (50ml) thoroughly washed with detergent, water, and petroleum ether were dried and weighed.
The bottle was filled with distilled water and weighed. After this the bottle was emptied, dried, then filled with oil and weighed. The specific gravity of the oil was calculated as:
Specific gravity =     Weight of xml of oil
                                    Weight of xml of water
Where x is the volume of the bottle
3.3.2 Acid Value or Free Fatty Acid Determination
The method described by Onwuka (2005) was used. 1g of the oil was weighed and poured into (250ml) conical flask. 25ml of diethyl ether  was poured into a 250ml conical flask. 25ml ethanol and 1ml phenolphthalein, were added and the mixture carefully neutralized with 0.1N NaOH, were shaken constantly till a pink colour was obtained. The acid value was calculated as:
Acid value = titre (ml) x 5.61
                        Weight of sample used
%FFA is calculated as palmitic acid,
FFA%= titre  (ml)   ×  0.0256             
             Weight of sample used
The FFA figure usually calculated as palmitic(1ml 0.1M NaOH≡ 0.0256g)

3.3.3 Iodine Value Determination:
The method described by Onwuka (2005) was used.1g of oil sample was weighed into a 250ml conical flask and 10ml of carbon tetrachloride added to it. The mixture was dissolved with 20ml wij’s solution after which the stopper that has been moistened with potassium iodide solution was inserted. This mixture was thoroughly mixed and allowed to stand in a dark cupboard for 30mins. At the end of the time, 15ml of potassium iodide solution and 100ml distilled water were added to the mixture and mixed properly. This was later titrated with 0.1M sodium thiosulphate solution using 1% starch as an indicator (aml).
A blank was carried out commencing with 10ml of carbon tetrachloride(bml).
Iodine value =          (b-a) x 1.269
                                    weight of sample used
where b                      =          titre value of blank
                a                  =           titre value of the sample

3.3.4               Saponification Value Determination
The method described by Onwuka (2005) was used. 2g of the oil was weighed into a conical flask and 25ml ethanolic potassium hydroxide solution added to it. A reflux condenser was attached to the conical flask after which the flask content was headed in boiling water for 1 hour with frequent shaking. About 1ml phenolphthalein (1%) solution was added and solution them titrated when hot with alkali. A blank was also carried out without addition of the extracted oil. The saponification value was expressed as:

Saponification value           =                      (b-a) x 28.05
                                                                   wt (g) of sample
where b          =          blank litre value
               a       =          sample titre value

3.3.5     Determination of Peroxide Value
The method described by Pearson (1976) was used to determine the peroxide value of the palm oil. 1g of the oil sample was weighed into a clean conical flask followed by 1g of powdered potassium iodide and 10ml of the solvent mixture (2 volume glacial acetic acid and 1 volume chloroform i.e. 2:1). The conical flask was placed on a boiling water bath so as to allow the mixture to boil vigorously for a time not exceeding 30 seconds; 20ml of potassium iodide solution (5%) was added and the mixture titrated with 0.002N sodium thiosulphate using (1%) starch as an indicator Peroxide value is given by
Peroxide value          =          (b-a) N x 100
                                    wt of the oil
where b         =          titre value of the blank
                        a          =          titre value of the sample
N         =          normality of the acid used.
 3.3.6 Melting Point
Oil was placed in a crucible and frozen in a refrigerator. The frozen oil was brought out and a thermometer placed in it. Beaker containing oil and thermometer was placed in hot water bath to warm. The  temperature at which the oil started to melts and completed were recorded. The temperature at which the oil completely melted was taken as the melting point.
3.3.7   Freezing Point
About 50ml of the oil sample was measured and poured into crucible dish. Then crucible dish was placed in a refrigerator and its temperature was taken and recorded as it initial temperature. The temperature was measured using thermometer. The temperature at which the oil sample got completely frozen was noted as the freezing point of the oil sample.        

4.1       RESULTS
Table 4.1 shows the effect of processing methods and storage time on some characteristics of palm oil.

Table 4.1:      Variation of physico-chemical properties of palm oil with processing method and storage time.

Processing methods
Storage time (Months)
0.910 + 0.014a
0.915 + 0.0071a
0.923 + 0.00424a
0.925 + 0.0071a
0.912 + 0.028a
0.912 + 0.01697a
0.9128 + 0.0099a
0.913 + 0.00283a
22.56 + 0.0849a
28.764 + 0.0198b
37.788 + 0.0396c
45.00 + 0.5657d
3.384 + 0.00849a
5.64 + 0.05657b
8.46 + 0.05657c
10.152 + 0.01697d
3.50 + 1.69706a
4.0 + 1.11723b
5.0 + 0.45255c
5.8 + 0.28284d
1.50 + 1.41421a
2.50 + 1.69706b
3.80 + 1.10309c
4.05 + 0.98995d
181.142 + 0.0283a
188.51 + 0.01414b
254.60 +  0.4243c
350.31 + 0.0283d
175.91 + 0.0141a
183.20 + 0.28284b
185.49 + 0.0283c
189.54 + 0.05657d
26.141 + 0.0566a
28.523 + 0.0424b
32.994 + 0.141c
37.0548 + 0.0283d
3.807 + 0.0141a
17.2584 + 0.0283b
28.695 + 0.0849c
34.7706 + 0.0849d
29 + 1.1414a
29 + 0.2828b
30+ 0.5657c
30 + 0.2828d
29 + 0.14142
32 + 1.14421b
34 + 0.42426c
37 + 0.28284d
26 + 1.14421a
27 + 0.28284b
27+ 1.14421c
28 + 0.28284d
23 + 0.4101a
24 + 0.1556b
24 + 0.1414c
24 + 0.4243d
Means with the same alphabet = no significant at 5% probability. SG = specific gravity,  FFA= free fatty acids, PV = Peroxide value, SV = saponification value, IV = iodine value, SP = smoke point,  FP = freezing point.

Fig 4.1. Variation of specific gravity of palm oil with processing method and storage time.


Fig 4.2. Variation of Free Fatty Acid of palm oil with processing method and storage time.

Fig 4.3. Variation of peroxide value of palm oil with processing method and storage time.

Fig 4.4. Variation of iodine value of palm oil with processing method and storage time.

Fig 4.5. Variation of saponification value of palm oil with processing method and storage time.

Fig 4.6. Variation of Freezing point of palm oil with processing method and storage time

Fig 4.7. Variation of melting point of palm oil with processing method and storage time.

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