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INTERDISCIPLINARY JOURNAL OF CONTEMPORARY RESEARCH IN BUSINESS
effect of phosphoric acid in the oil was neutralised. The bleaching process was carried
out with continuous stirring. The bleached oil was filtered cloth sieve (pap sieve) and
filter paper respectively.
15.8 DEODORISING PROCESS.
A distillation set up was used for the oil deodorisation. One of the round bottom flask
was place inside a pot containing boiling water of 250 o C . This temperature was
maintained to allow the free fatty acid (FFA) and other volatile components as well as
odour to be stripped off from the oil. Citric acid was added as a preservative to enhance
the oil‘s shelf-life. FFA , steam and other components that were stripped off, were
collected in another round bottom flask. The process was allowed for 30 minutes.
16. RESULT AND DISCUSSION
This chapter analyses the results obtained from the materials and methodology chapter.
The result obtained from the free fatty acid(FFA) analysis of the crude palm kernel
oil(PKO) shows that the free fatty acid content in the palm kernel oil is 2.8%, which is
0.3% higher than the standard value( 2.5%).This is as a result time difference between oil
extraction period and the refining period.
FFA is as a result of hydrolysis of fats, and moisture must be present for hydrolysis to
take place. The moisture and volatile content analysis of the of the crude palm kernel oil
showed 0.4% which is 0.1% above specification. This also contributes to the percentage
FFA above specification. The FFA of the crude is usually dependent on the
enzymatic(lipase) in the palm kernel before extraction and on the charring of the kernel.
Other minor constituent of crude palm kernel oil include traces of hydrocarbon, ketones
and other unidentifiable materials which gives the individual member their distinctive
odour and flavours.
The peroxide value analysis of the crude palm kernel oil showed that the peroxide is 0.75
which is within the acceptable limit.
During the bleaching and degumming process, the pigments as well as the gums, metal
traces, soap traces if any and other impurities in the oil were removed. Most of these
products are removed after the continuous stirring of the oil with an adequate bleaching
earth for a given period of time at temperature between 90 o C and 110 o C. The quality of
the bleaching earth is of utmost important also the capacity of the bleaching earth which
determines the amount of leaching earth that is required to obtain the desired result. The
quantity of bleaching earth used for this experiment was 15%. Natural colouring matters
were easily removed but the colours that were developed in the crude oil were difficult to
eliminate. The colours that were developed/fixed in the crude PKO could be as a result of
prolong storage, excessive heating of oilseeds during extraction or by prolong crude oil
storage at high temperature.
Also, during deodorising process, odorous and flavouring matters which are mainly
aldehydes, ketones, alcohols and hydrocarbons are removed at the same time as the free
fatty acid. Some unsaponifiables such as tocopherols are evaporated at the same time
because they are more volatile than the oil at the temperature of 250 o C. The rate of the
removal of these materials is proportional to length of time the oil remains in the
deodoriser and tonne the temperature at which the deodorisation takes place.
COPY RIGHT © 2011 Institute of Interdisciplinary Business Research 80
JANUARY 2011
VOL 2, NO 9