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Abstract
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Fatty
Acid Composition of Edible Oils in the Malaysian Market, with Special Reference
to the Trans-fatty Acids
A total
of 113 samples of various types of palm and palm kernel oil products, their
fractions, palm-based and non-palm-based cooking oils obtained from local
manufacturers and the retail market were analysed for their trans-fatty
acid compositions and contents by capillary gas chromatography. Trans-fatty
acids were generally absent in crude palm and palm kernel oils. However,
they were present at 0.01%-0.06% in refined palm kernel products and 0%-0.61%
in refined palm products, all well below the 1.0% level stipulated by some
importers. These trans-fatty acids were formed from their natural cis -isomers
as a result of the high temperature used during deodorization.
In cooking
oil, the trans-fatty acid contents of palm-based products were 0.25%-0.67%,
again well below 1%. However, in the non-palm-based cooking oils, the contents
of the 14 samples ranged from 0.43%-3.83%. The higher contents in the non-palm-based
oils were expected as they had high contents of unsaturated fatty acids,
which are more prone to isomerization at elevated temperatures.
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Preparation
of Cellulose from Oil Palm Empty Fruit Bunches Via Ethanol Digestion: Effect
of Acid and Alkali Catalysts
Ethanol
digestion of oil palm empty fruit bunches (OPEFB) fibres at a temperature
between 165ºC - 180ºC for 2 hr and at a solid-to-liquid ratio
of 10:1, ethanol-to-water ratio of 1:1, and with or without 10% 1 N HCl
and 1.25 M NaOH as catalysts was studied in order to prepare cellulose
via ethanol pulping. The pulp produced was studied for yield, moisture
content, solubility in cold/hot water and 1% NaOH, lignin, holocellulose
and alpha-cellulose content.
The highest
yield of pulp (57%, oven dried weight basis) was from OPEFB fibres digested
at 170ºC for 2 hr without addition of catalyst, whereas OPEFB fibres
digested at 175ºC for 2 hr with acid catalyst gave the lowest yield
of 45% (oven dried weight basis) pulp. Higher cooking temperature gave
lower yield of pulp since the reaction hydrolyzed out the hemicellulose,
lignin and part of the cellulose. The reactions at 165ºC, 170ºC
and 175ºC with acid catalyst produced 56%, 50% and 45% of pulp yield,
respectively. It was found that a temperature of 180ºC with or without
catalyst was too high for pulping because it totally digested the fibre
into a viscous soluble pulp.
On the
effect of catalysts, acid catalyst was found to enhance the pulping of
OPEFB fibres. Without the acid catalyst, at temperature of 165ºC,
the fibres could not be fully cooked and would still be in the fibrous
form. Reactions at 170ºC and 175ºC without catalyst gave 57%
and 55% yield of pulp, respectively whereas with acid catalyst gave 50%
and 45% yield of pulp respectively. The base catalyst could only fully
pulp the OPEFB fibres at a temperature of 175ºC, but the fibres dissolved
at temperature 180ºC.
Pulp
produced at 175ºC for 2 hr with 10% 1.25 M NaOH gave the best quality
pulp, which contained lowest lignin and highest holocellulose at 8.2% and
91.8% (based on the dry weight of pulp), respectively. The maximum yield
of ?-cellulose (isolated from the pulp) also was obtained from OPEFB digested
with alkali catalyst at 175ºC for 2 hr (64.3% based from dry weight
of pulp; 34.1% based on dry weight of OPEFB).
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Performance
and Heritability Estimations on Oil Palm Progenies Tested in Different
Environments
Forty
oil palm (Elaeis guineensis Jacq.) dura x pisifera (DxP) crosses derived
from the North Carolina Mating Design 1 (NCM 1) were evaluated in six locations
(Kudat, Sabah; Beaufort, Sabah; Teluk Intan, Perak; Carey Island, Selangor;
Kepong, Selangor and Kluang, Johor). Fifteen pisifera palms were chosen
as male parents and each was crossed to two to four dura female parents.
Environmental
factors contributed to the phenotypic variability in all the agronomic
characters. Hence, the variation in performance of the genotypes in the
different locations was partly a reflection of the differences in soil
type, soil fertility and rainfall. Generally, Carey Island and Teluk Intan
were the more favourable environments for yield than the marginal environments,
such as Kudat and Kluang.
The results
showed that the environment had a great influence on the genetic variance
components. In general, the heritability estimates for yield and its components
and bunch quality characters fluctuated from location to location. However,
the estimates for vegetative characters were fairly consistent and higher
than those for yield and its components, and bunch quality characters.
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Chemical
Composition of Oil Droplets from Palm Oil Mill Sludge
Oil droplets
from the centrifuge sludge of a palm oil mill were separated by high speed
centrifugation, dried and extracted with organic solvents, methanol and
chloroform. The oil droplets (73 wt %) was solvent extractable. The extract
was determined to consist of 84 wt % neutral lipids and 14 wt % of complex
lipids (6 wt% glycolipids and 10 wt% phospholipids). The neutral lipids
consisted of 83% triglycerides, 8% diglycerides, 0.5% monoglycerides and
8.0% free fatty acids.
Five
types of glycolipids were determined and identified as digalactosyl diglycerides
(22%), steryl glycosides (17%), cerebroside (9%), monogalactosyl diglycerides
(20%) and esterified steryl glycoside (26%). Five types of phospholipids
were determined and identified. They were phosphatidylethanolamine (21%),
phosphatidylglycerol (37%), phosphatidylcholine (17%) and phosphatidylserine
together with phosphatidylinositol at 11%. Palmitic acid (C16:0) and oleic
acid (C18:1) were the major fatty acids found in the lipids.
The oil
droplets found in the sludge were not unruptured oil droplets inherent
in ripe mesocarp or young palm fruits. From the chemical analysis of the
lipids associated with the oil droplets, it was deduced that oil droplets
from the sludge are indeed formed in the milling process and possibly stabilized
by the surface active agents of mainly phospholipids and glycolipids. The
relatively high concentration of such biosurfactant in the oil droplets
may have commercial potential as a value-added resource from the palm oil
milling process.
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Microstructure
of Medium Density Fibreboard from Oil Palm Empty Fruit Bunch Fibre
Using sequentially
acquired 2-D images of microtome sections via a light microscope, 3-D
models of the microstructure of commercial and laboratory produced medium
density fibreboards (MDF) were constructed. To assess the accuracy of
the 3-D models, they were analysed for their ratios of inter-fibre void
using an image analysis technique. The study indicated that it was feasible
to use this technique to determine the variation in inter-fibre void
ratio at different depths in the MDF. The ratio of void area varied
significantly in a gradient from the top/bottom of the boards to the
core (middle). However, in the other directions (along the length and
breadth), there were no significant differences in the void ratio. The
ratio of void area within each panel was negatively related to the density.
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The
Effect of Disalt on the Biodegradability of Methyl Ester Sulphonates (MES)
The biodegradability
of methyl ester sulphonates (MES) was found to be affected by the disodium
salt (disalt) content. The higher the disalt content, the lower is the
biodegradability of MES. Disalt has a lower surface activity and is sparingly
soluble in water when compared to the monosodium salt MES. These characteristics
lower the biodegradability of disalt when compared to the monosodium salt.
The biodegradability of a commercial MES sample was found to be better
than linear alkylbenzene sulphonates (LAS), thus offering an additional
advantage for the commercialization of oleochemical-based surfactant.
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