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Abstract |
Transesterification
of Palm Oil: Effect of Reaction Parameters
The most practical and suitable method
for industrial production of methyl esters of palm oils with negligible
free fatty acids (e.g. neutralized palm oil and refined, bleached and
deodorized palm oil) is methanolysis of the glycerides catalyzed by
sodium hydroxide. Several parts including the type of catalyst, oil/alcohol
ratio, temperature, stirring speed and free fatty acids content, have
been found to influence the transesterification of palm oil. Optimum
reaction conditions were obtained with a molar ratio of methanol-to-oil
at 10:1 and a reaction time of 7 min at ca. 65½C. The rate of
reaction was optimized at a stirring speed of 150 rpm. The minimum amount
of methanol required to achieve total conversion was 233% (excess methanol)
(a methanol-to-oil molar ratio of 10:1). The catalyst used should not
exceed 0.5 mole kg -1 oil as otherwise it would cause solidification
of the reaction mixture due to soap formation. For a large number of
glyceride oils containing <5% free fatty acids, transesterification
to methyl esters can be readily effected using additional sodium hydroxide
to neutralize the free fatty acids. Glycerol from the transesterification
process was purified from 80%-85% to more than 96% with a yield of not
less than 75%.
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Selection
of Partial Resistance in Oil Palm Progenies to Ganoderma
Basal Stem Rot
The development of Elaeis guineensis
progenies resistant to Ganoderma may provide the ideal long-term
solution to basal stem rot, a major disease of oil palm in Malaysia
and Indonesia. A study was conducted to select different oil palm
progenies for resistance to G. boninense infection. In this
study, 12-month-old seedlings from 23 progenies, namely, three DxD,
six DxP, three OxO, one OxP, five TxP and five TxT were inoculated
with G. boninense using the root inoculation technique. External
foliar symptoms developing on seedlings were recorded for a period
of 12 months. Twelve months after inoculation, all the seedlings were
examined for internal symptoms based on the length of inoculated root
lesioned, number of primary roots infected and extent of stem bulb
tissues lesioned. Based on reisolation of G. boninense from
inoculated seedlings, it was shown that all 23 progenies from the
different oil palm crosses were infected by G. boninense.
The uninoculated seedlings for each of progenies did not show any
signs of disease symptoms or lesions and G. boninense was
not present. Some 25.6% of the inoculated seedlings were dead due
to G. boninense infection, and there were significant differences
between the progenies tested for the severity of foliar symptoms measured.
For internal symptoms, there was no significant difference in the
length of inoculated roots lesioned. However, the number of primary
roots infected and extent of stem bulb tissues lesioned were significantly
different. Of the 23 progenies, the most susceptible progeny was PK
2724 [DxD, Deli (Elmina) x Deli (Elmina)], whilst a partially resistant
progeny was PK 2567 (DxP, Congo x Cameroon). Partial resistance is
expressed by low severity of foliar symptoms and slow progress of
Ganoderma infection in the roots and stem tissues.
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Kinetics
Study on Transesterification of Palm Oil
The kinetics of base-catalyzed transesterification
of palm oil based on parameters such as oil and alcohol ratio, catalyst
concentration and temperature were investigated to optimize the conversion
rate. Our findings showed that both sodium hydroxide and sodium methoxide
had high kinetic constants depicting fast formation of palm oil methyl
esters with conversions above 99%. Fast formation of palm oil methyl
esters with a rate constant of 0.163 litre mole min -1
was obtained when the reaction parameters were: molar ratio of oil to
methanol, 1:10; catalyst concentration, 0.125 mole kg -1
oil; and temperature, 60½C.
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Optimization
of the Sweep Co-Distillation Clean-Up Method for the Determination of
Organochlorine Pesticide Residues in Palm Oil
The optimum conditions were developed
for the quantitative recovery of organochlorine pesticide residues in
palm oil using a commercial sweep co-distillation apparatus. Under the
optimum conditions (245 oC
distillation temperature, 250 ml min -1nitrogen
flow rate, 45 min sweep time) and using a trap packed with sodium sulphate
and partially deactivated Florisil, the recoveries of 14 organochlorine
pesticide residues at ppm and ppb levels in a spiked oil matrix were
>80%, with coefficients of variation ranging from 5.6% - 9.9%. However,
the recovery for endrin ketone was below 80% with a coefficient of variation
of 8.5%. The cleaned-up extracts were quantified by gas chromatography
using a micro-electron capture detector with a fused silica capillary
column containing a non-polar bonded phase.
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Synthesis
of 2-Substituted 4(R)-Hydroxy-2-Cyclopenten-1-One, a Prostaglandin Intermediate
with Methyl Oleate from Palm Oil
Methyl oleate, 1 was
obtained from palm methyl esters through removal of saturated esters
in a urea complex formation followed by silver nitrate impregnated silica
gel column chromatography. The oleate was then reacted with 2,3-O-isopropylidene-D-glyceraldehyde
2, to form an aldol compound which, after lactonization, formation of
tosylate and cyclic cyanohydrin, and oxidation of the double bond afforded
2-(6--carbomethoxyhexyl)-4(R)-hydroxy-2-cyclopenten-1-one 11, a prostaglandin
intermediate.
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Multiplication
of Oil Palm Suspension Cultures in a Bnech-Top (2-litre) Bioreactor
Oil palm Elaeis
guineensis suspension cultures were multiplied in a B-Braun Biostat
® B’ 2L version 1.0 bioreactor. An initial experiment using
the original system was not successful as most of the culture aggregates
lodged between the baffle cage and inner wall of the vessel and also
between the blades of the impeller. This damaged the aggregates. Some
modifications were then made to the bioreactor by replacing the impeller,
baffle cage and microsparger. After modification, the cultures showed
good proliferation with about 10- to 14- fold weight increment after
50 to 80 days. Thus, the B-Braun bioreactor with slight modification
has the potential for large scale multiplication of oil palm suspension
cultures.
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Life
Cycle of Sycanus dichotomus (Hemiptera: Pentatomidae) - a Common
Predator of Bagworm in Oil Palm
The life cycle of
Sycanus dichotomus (Hemiptera: Reduviidae) was studied with
two types of prey, Corcyra cephalonica and Plutella xylostella
in a controlled environment room. The eggs hatched after 11 to 39 days
with each cluster having 15 to 119 eggs. Five nymphal stages were recorded.
The mean longevity of each nymphal stage was 24.35, 16.95, 20.35, 25.32
and 43.51 days when fed with C. cephalonica and 16.72, 15.78, 14.88,
24.03 and 46.84 days when fed with P. xylostella. The period
of development from eggs to adult when fed with C. cephalonica
and P. xylostella were 193.44 ± 2.41 and 203.91 ±
2.77 days. The mean longevity for male and female adults fed with P.
xylostella was 83.47± 4.37 and 87.64 ± 3.31days respectively.
The longevity of male and female adults fed with C. cephalonica
was 63.99 ± 2.92 and 61.61.86 ± 2.96 days. Lower mortality
was recorded on the S. dichotomus fed with P. xylostella.
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Degumming
and Bleaching: Effect on Selected Constituents of Palm Oil
Degumming and bleaching are essential
processes in palm oil refining. The purpose is the removal of gums,
trace metals, pigments, peroxides, oxidation products and other breakdown
products in the crude oil by adsorption on the active surface of the
bleaching earth to improve colour and stability of the final oil. This
paper aims to study the effect of degumming and bleaching using neutral
and acid-activated clays to achieve the aforementioned objectives. It
was found that valuable palm minor components, i.e. [tocols (tocopherol
and tocotrienols) were retained; no significant changes occurred in
the total phytosterols, squalene, composition of acylglycerols (i.e.
mono-, di- and triacylglycerols)] and free fatty acids by using both
acid-activated and neutral clays up to 1.0%. However, acid-activated
clay reduced the carotenes content. Both clays gave markedly improved
oxidative stability with induction period >30 hr at 120 oC.
Impurities such as pro-oxidant iron, copper and phosphorus were reduced
by both clays. The bleaching effect of neutral clay was relatively poor
compared to acid-activated clay in the removal of unwanted compounds.
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Immigration
and Activity of Oryctes rhinoceros Within a Small Oil Palm
Replanting Area
The pheromone of the rhinoceros beetle
(Oryctes rhinoceros) has been used for mass trapping and monitoring,
integrated with biological control agents. In the current study, pheromone
traps were used to monitor the immigration and activity pattern of Oryctes
adults within a 4.5 ha replanting block. Trapping was initiated after
about five months of replanting, for a period of 24 months. The relationships
of the trap captures with the heap population, palm damage, rainfall
and moon phases were also studied. Infestation of the block occurred
almost simultaneously with replanting. The core region of the block
was infested between the fourth to seventh month after completion of
felling and chipping. It was noted that female beetles were trapped
consistently more at the fringes than in the core of the replanting
block. There was a significant relationship between the number of adult
females trapped (at about 40-60 days before monitoring the population
in the heaps) and the number of second instar larvae. There was an increase
in the flight activity of the beetle (based on trap captures) during
wet weather, likely due to their search for moist breeding sites. Male
beetles were more active during the full moon, likely navigating for
food and searching for suitable habitats before mating. Cumulative captures
of each individual trap and the damage levels of adjacent palms were
significantly related. A high proportion (92%) of females captured in
the traps were gravid, with a mean of 16 eggs per female. Based on trap
captures, there were indications that adult populations were coming
from the adjacent mature plantings. This information can be exploited
for more effective and targeted control of the pest.
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The
Effects of Oils on Germination of Beauveria bassiana (Balsamo)
Vuillemin and its Infection Against the Oil Palm Bagworm, Metisa
Plana (Walker)
This study reports the effects
of oils on the conidial germination of four strains of Beauveria
bassiana (Balsamo) Vuillemin (F1, F5, F8 and F10) and their infectivity
against the larvae of the oil palm bagworm, Metisa plana
Walker. The effects of the oils and age of the conidia on the germination
of the conidia were examined in the first experiment. Of the five
oils tested, soyabean oil and paraffin gave the highest germination
for both two- and four-week-old conidia. Palm and corn oils completely
inhibited the conidial germination. Germination was influenced by
the age of conidia with the mature conidia germinating better than
the younger conidia. The pathogenicity of all the four strains of
B. bassiana conidia formulated in soyabean oil against the
larvae of M. plana revealed that more than 95% mortality
at 10 days after treatment. Although Strain F5 produced the lowest
LT 50 (2.6 days), based on the mortality rate and percentage infection,
Strain F10 was the more pathogenic. The short (254 nm) ultraviolet
radiation was more detrimental to the conidia compared to the long
(365 nm) ultraviolet radiation. Soyabean and paraffin oils gave a
similar level of protection to the conidia but oil with 1% (w/v) sunscreen
gave significantly better protection. Strain F10 was more stable than
Strain F5 to both wavelengths of ultraviolet radiation. B. bassiana
conidia formulated in oil plus 1% sunscreen and oil alone caused about
12 and 15 times higher mortality against the larvae of M. plana
than the water formulation. The advantages of using oil over water
for the formulation of B. bassiana to control M. plana
in the field are discussed.
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Seasonal
Variation in Yield and Developmental Processes in an Oil Palm Density
Trial on a Peat Soil: 1. Yield and Bunch Number Components
Bunch production in an oil palm density trial on a
peat soil in Perak, West Malaysia, displayed a regular annual cycle
that was highly synchronized across densities. The phase of the cycle
differed from that displayed for West Malaysia as a whole but resembled
those at some other sites. Annual cycles were found in both bunch
number and mean bunch weight and in the proportion of palms that yielded
bunches in any one month. While the long-term trends in bunch numbers
and single bunch weights were negatively correlated, in the short-term
there was a highly significant positive correlation between the two.
The variation in mean bunch
weight was also reflected in the variation in the main bunch components.
There were also seasonal variations in the ratios of bunch components.
In addition to yield, regular
annual cycles were also apparent in the rates of frond emission, male
and female inflorescence production and sex ratio, and in inflorescence
abortion. While the phases of bunch and female inflorescence cycles
could be matched using physiologically meaningful lag periods, the
cycles of frond emission and total inflorescence production, and of
frond emission and female inflorescence production could not, giving
rise to non-significant or negative correlations.
Abortion rates were low
throughout the trial and while a regular sex ratio cycle became apparent
from the eighth year, this was not the main determinant of bunch number
cycling. Rather, variation in the rates of inflorescence development
may be the crucial factor in causing the yield cycles. Other external
and internal factors that might contribute to the yield cycles are
discussed.
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Seasonal
Variation in Yield and Developmental Processes in an Oil Palm Density
Trial on a Peat Soil: 2. Bunch Weight Components
Short-term changes in bunch weight were found to contribute
to seasonal yield cycles in an oil palm density trial on a peat soil
in Perak, West Malaysia. Unusually, the cycle in bunch weight was in
phase with that in bunch number. The results of bunch analyses carried
out over a 10-year period were examined to identify whether cycles also
occurred in bunch components and to examine the effects on oil and kernel
yields. The analysis showed that total fruit weight per bunch fluctuated
more than the weight of the bunch frame, while within the fruit, the
mesocarp showed a greater variation in weight per bunch than the nut.
However, while the seasonal changes in fruit-to-bunch (F/B) on a mean
monthly basis over years were significant, there were no comparable
significant changes in the other bunch component ratios.
There
was some evidence based on changes in single fruit weight and fruit
number that the changes in F/B might be due to variation in pollination
efficiency.
The
variation in mesocarp weight per bunch was attributable to variation
in both the oil and water contents with little change in the fibre.
Similarly, within the nut, the larger shell component tended to vary
more than the kernel.
The
contribution of bunch weight variation to the variation in total yield
and its relationship to bunch number are discussed.
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Selecting
the Ideal Oil Palm: What You See is Not Necessarily What You Get!
Yield is the most important selection trait for the ideal
plant. Yield selection on single plants from segregating populations
in the early selection cycle is unreliable because of unstable genotypes,
low heritability and differential plant competitive abilities. Yield
selection is best done in later cycles when sufficient quantities of
the selected stable genotypes are available for replicated larger plot
yield trials conducted over different locations and agronomic treatments.
Breeding progress for yield in major crops has been generally slow at
1% -2% per year but nevertheless significant. Methods, e.g. breeding,
physiological, biotechnological, to improve selection efficiency and
shorten the selection cycles are not likely to substantially reduce
the cultivar development time because of the mandatory extended cycles
of yield testing. A smaller erect canopied palm with high harvest index
that can tolerate higher density planting would be the oil palm ideotype
for efficient yield enhancement. Such cultivars are unlikely to be available
for the next 15 years. Nevertheless, plantations should accelerate replanting
as improved cultivars particularly with better oil content are continuously
being produced, and coupled with the simultaneous implementation of
improved agro-management practices, larger quantum yields can be achieved.
Existing planted materials already have high genetic yield potential,
and the onus lies with the agronomist and manager to implement the prescribed
agro-management practices to achieve the yield potential of the site
and thus, narrow the gap between potential and realized yields.
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