Physico-Chemical Analysis of Pycnanthus (Pycnanthus Angolensis) Seed Oil

Table of Contents

INTRODUCTION – PYCNANTHUS ANGOLENSIS

FUNCTIONAL USES

MATERIALS AND METHODOLOGY

RESULT AND DISCUSSION

REFERENCES

ABSTRACT

This study was based on physico-chemical analysis of the oil content of Pycnanthus seed for its potential and industrial uses. Seeds were collected from Pycnanthus tree at Awba-dam, UI Ibadan. The results obtained are oil extract 48%, the specific gravity 0.978, refractive index 1.4521, melting point 500C, the saponification value 245.44%, acid value 6.21mg(OH)/g oil, peroxide value 16.12mEq/kg and ester value 239.23. The iodine value of seed oil which placed the oil in the non-drying group was 84.94. Fatty acid composition of the seed oil showed the oil to be rich in lauric acid 64.72%, palmitic acid 13.97%, capric acid 4.99%, capryclic acid 4.40%, myristic acid 4.33% and stearic acid 1.93%. It also contained oleic acid 3.26% and linoleic acid 2.40%. The other fatty acids present in the oil are palmitoleic acid, Linolenic acid and Llignoceric acid. The seeds of the plant could be a source of industrial raw material

Key words : Pycnanthus angolesis, Specific gravity, Iodine value, Refractive index and Fat content

INTRODUCTION – PYCNANTHUS ANGOLENSIS

“ Akomu” tree is biologically called Pycnanthus Angolenis. It is called African nutmeg in English, Akwa-mili in Igbo, Lunaba in Luganda, Calabo in Spanish. The trade name given to this tree is Ilomba while it is called Akomu in Yoruba. African nutmeg belongs to the family of Myristicacease (Center Technique forestier Tropical 1961). Parts of the plant are widely reported to have several medicinal value (Agyare et al., 2009). The leaf and bark are used to treat toothache and the sap of of the plant is applied topically to arrest bleeding (Abbiw, 1990).

Pycnnthus angolensis is a tree of about 25 – 35 (40) m high and 60 – 100 (150) cm in diameter, occasionally more, evergreen, bole straight, cylindrical, without buttresses, bark grey, longitudinally fissured, flacking in patches , in old trees, slash reddish, exuding a sticky, honey – coloured sap turning red. The leaves are so often eaten by insects that this is a characteristic feature (Abbiw, 1990).

Fruits (often occuring within the flowers) ellipsoid or almost spherical drupe shape, 2.5 – 3.8cm long and 1.9 – 3.2cm in diameter, often indense clusters at the base of the twigs, opening by 2 values and exposing a solitary black seed with a bright red arill much branched at the apex. The generic name, Pycnanthus is derived from Greek, the literary meaning is ‘dense flowers’ and it refers to the numerous flowers crowded together. It is distributed across the native such as Benin, Congo, Cameroon, Cote d’Ivore, Nigeria, Senegal , Uganda (Abbiw, 1990)

The evergreen tree is the monoecious, with the asexual flowers on different parts of the same branch. In its natural habitat, the flowers are produced in October and November, at the same time on the tree until about February. Deliscence takes place on the tree, but many of the fruit clusters fall unopened (Dupuy, 1993).

FUNCTIONAL USES

Pycnanthus angolensis tree serves a lot of functions. It is used as fuel where the seeds burn like candles and seed oil is an illuminant in West Africa(Arbonncer, 2004). As lipids, the oil is extracted from the seeds and used in making soap. Medically, bark decoction is an emetopurgative and can act as an antidote to poisonig; used in treating leprosy and, if pounded, used to treat stomachache (Keay et al., 1964). Its Sap acts as a septic (arrests bleeding). Leaf and bark help to relieve tootache (Abbiw, 1990). Seed fat and probably leaf juice is used in treating thrush. Root infusion acts as an anthelmintic (Abbiw, 1990). It is used as timber whereby the wood obtained is grayish white or tinged with pink. The wood is light, very soft, of medium nervosity and shrinkage. Its natural durability is low, but it is easily machined. During seasoning the wood sometimes warps (Udeozo et al., 2011).

This easily worked, and straight-gained wood is used for veneer peeling, panels, furniture frames, box making and minor joinery. In Cameroon, It is split into rough planks for house building and roofing materials (Arbonncer, 2004)

MATERIALS AND METHODOLOGY

SAMPLE COLLECTION

Pycnanthus seeds were obtained from the Pycnanthus tree at Awba-Dam, University of Ibadan, Oyo State, Nigeria in the Month of June, 2015.

SAMPLE PREPARATION

The seeds were washed with water to remove the unwanted materials, afterwards, the seed were cut into pieces so as to aid effective drying. They were then sundried in the sunlight for two weeks and again dried oven at 400C for an hour. The seeds were grounded into powder and kept in a sealed container.

DETERMINATION OF PHYSICAL AND CHEMICAL PROPERTIES OF PYCNANTHUS SEED OIL

The parameters analysed were melting point specific gravity, saponification value, acid value, iodine value, refractive index, lipid.

CRUDE FAT DETERMINATION

SOLVENT SELECTION

The idea solvent for lipid extraction is one, which could completely extract all the lipid from the sample while leaving all other component behind (Rosenbery, 1998).

From this research work, hexane is chosen because it is non-polar, non-toxic and easily be removed by evaporation (Ibitoye, 1996).

EXTRACTION METHOD

The batch solvent extraction (cold extraction) was used for this work.

BATCH SOLVENT EXTRACTION

40 g of the dried sample was weighed into a separatory funnel and about 250cm3 of the solvent (hexame) was added. The separatory funnel containing the mixture was vigorously shaken intermittently.

It was then allowed to stay for 24 – 48 hours to ensure adequate extraction and settlement.

The acqueous phase was then decanted off and the solvent was allows to ecaporate leaving behind the lipid.

illustration not visible in this excerpt

Where:

W1 =weight of fresh sample=40g

W2 =weight of sample after=20.8g

The mass of the lipid was measured to determine the amount of the lipid extracted.

(Morris, 1999)

MELTING POINT DETERMINATION

The fat sample was melted and drawn into a capillary tube. The tube containing, the sample was then placed in a refrigerator between 5 oC - 10 oC for 18 hrs for the oil to solidify. The sample was then placed in amelting point apparatus and observed until it began to melt. The temperature range at which melting occurred was noted and recorded as the melting (AOCS, 1994).

SAPONIFICATION VALUE

2g of oil was weighed into a conical flask, 25cm3 of 0.5M alcoholic KOH was added. A blank was prepared by putting 25cm3 of the alcoholic KOH in a similar flask reflux condenser was fitted to the flask containing the mixture, this was heated in a water bath for one hour, swirling the flask from time to time. The flask was the allowed to cool a little and the condenser was washed down with a little distilled water, the excess KOH was titrated with 0.5M HCL using phenolphthalein indicator.

The saponification value was calculated from the difference between the blank and the sample titration.

illustration not visible in this excerpt

Weight of sample

Where: a = titre value of sample

b = titre value of blank

f = factor of 0.5M HCL

28.05 = mg of KOH equivalent to 1cm3 of 0.5M HCL

Weight of sample = 2g (Morris, 1999)

ACID VALUE

0.1g of the oil was dissolved in 2.5cm3 of 1: 1v/v ethanol: diethyl ether solvent and titrated with 0.1N sodium hydroxide while swirling using phenolphthalein as indicator.

The acid value was calculated using the formula:

illustration not visible in this excerpt

Where: N = the normality of sodium hydroxide

V = the volume of sodium hydroxide in cm3

W = weight of the sample = 0.1g (Morris, 1999)

ESTER VALUE

This was obtained by finding the difference between the saponification value (S.V) and Acid value (A.V) (Morris, 1999)

PEROXIDE VALUE

5g of the oil sample was dissolved in 30cm3 of a slovent mixture consisting of 60% glacial acetic acid and 40% of chloroform. 0.5cm3 of a saturated solution of potassium iodide was added. The flask was shaken until the solution became clear. After 2 minutes from the time of addition of KI, 30cm3 of distilled water was added and titrated with 0.01N sodium thiosulphate solutions. It was then shaken vigorously to remove the last traces of iodine from the chloroform layer.

illustration not visible in this excerpt

Where: ML = titre value

N = normality of Na2S2O3 solution

W = weight of the oil sample = 5g (Morris,1999)

IODINE VALUE

1g of oil was weighed into a conical flask. 10cm3 carbon tetrachloride was added, then 20cm3 of wijs solution was added and the flask was covered, mixed and allowed to stand in the dark for thirty minutes. 10% potassium iodine was prepared by wighing 10g and dissolved it in 100cm3 of distilled water. Then 15cm3 of the prepared 10% KI solution and 100cm3 distilled water were added to the content in the flask. It was mixed thoroughly and titrated against 1.0N thiosulphate solution. Starch indicator was uded and blank determination was carried out under the same condition.

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