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VOLUME 12 NO. 2, December 2000

COMPOSITIONAL AND DIFFERENTIAL SCANNING CALORIMETRY (DSC) STUDIES OF CRYSTALS OF PALM OLEIN

SIEW, L L and FARIDAH MD JAAFAR

The composition and thermal properties of palm olein upon storage have been investigated by numerous techniques such as Differential Scanning Calorimetry (DSC), Gas Chromatography (GC) and High Performance Liquid Chromatography (HPLC). DSC melting and crystallization thermograms of crystals separated from palm olein differed in their characteristics, according to the composition of the olein and the storage conditions. A comparison was made between oleins of iodine value (IV) in the range of 56-61 which were stored at conditions of 20°C and 5°C. The more unsaturated olein was stored at 5ºC. Oleins with higher unsaturations showed crystals with a group of exotherms and endotherms which generally did not differ much with duration of storage. Crystals of the more saturated types of olein still retained the two exothermic and endothermic peaks, as observed in palm oil. The crystals of unsaturated oleins (IV of 60.6) tended to have a higher proportion of POO than POP, in contrast to the crystals of oleins (IV of 57.7) where the POP content is higher. With longer storage period, these exotherms and endotherms were shifted closer together, depicting polymorphism upon melting. With a long duration of storage, as in ambient storage conditions, another set of olein samples resulted in crystals with harder characteristics and a melting point of about 68°C. These crystals contained high diglycerides, confirming earlier works on the strong role of diglycerides in the crystallization stability of palm olein.  

SYNTHESIS AND CHARACTERIZATION OF ACETYLATED GLUCOSE FATTY ESTERS FROM PALM AND PALM KERNEL OIL FATTY METHYL ESTERS

DZULKEFLY KUANG, OLOBO J OBAJE and ABDUL MANAF ALI

Acetylated glucose fatty esters (AGFE) were synthesized from palm and palm kernel fatty acid methyl esters (FAME) through a one-stage solvent-free interesterfication reaction with glucose pentaacetate (GPA). Two main products obtained and identified were mono-and di-substituted AGFEE. The hydrophile-lipophile balance (HLB), ternary phase diagram, cytotoxicity and antimicrobial bioassays were studied.

PHYSICO-CHEMICAL PROPERTIES OF BINARY SYSTEMS OF ALPHA-SULPHONATED ETHYL ESTER DERIVED FROM PALM STEARIN AND NONIONIC SURFACTANTS

LIM, W H, SALMIAH AHMAD and ZAHARIAH ISMAIL

The effects of mixing sodium alpha-sulphonated methyl ester derived from palm stearin salt ( a-SMEPS) with nonylphenol ethoxylate alcohol (NONIPOL) and polyoxyethylene (20) sorbitan monoester (TWEEN) in mixed micelles systems were studied as a function of their weight ratios. Changes in the critical micelle concentration (CMC) and surface tension were observed at different weight ratios of the mixed surfactant. Incorporating the nonionic surfactants into a-SMEPS solution changed the surface properties of the system by lowering the Kraft temperature and decreasing the foaming stability. The effects of these mixed anionic-nonionic surfactant were due to inter-action between the different hydrophobic and hydrophilic portions of the surfactants.

NUTRIENT CYCLING IN AN OIL PALM PLANTATION: THE EFFECTS OF RESIDUE MANAGEMENT PRACTICES DURING REPLANTING ON DRY MATTER AND NUTRIENT UPTAKE OF YOUNG PALMS

KHALID HARON, ZIN Z ZAKARIA and ANDERSON, J M

Oil palm residues during replanting contributed significant amount of nutrients that can be recycled in the plantation. The management of oil palm residues affects the release of nutrients and hence their uptake and the growth of young palms. Dry matter and nutrient uptake of young palms and ground cover were estimated. Planting young palms directly onto the residue pile is the most effective method of biomass management during replanting as it provides better synchronization between nutrient release and plant uptake.

The young palms only utilized about 10% - 20% of the total nutrient uptake that is mostly found in the fronds. The young palms planted onto the residue pile is the most effective method of biomass management during replanting as it provides better synchronization between nutrient release and plant uptake.

The young palms only utilized about 10%-20% of the total nutrient uptake that is mostly found in the fronds. The young palms planted onto the residue pile without inorganic fertilizer inputs immobilized about 30 kg N ha-1, 3 kg P ha 43 kg K ha-1 , 6 Ca ha-1 and 4 kg Mg ha-1, over the 18-month period of assessment. The results obtained showed that the chipped and shredded (C / S) treatment was the most efficient. More than 80% of the nutrients were consumed by the ground cover which comprised legumes and weeds. The ground cover immobilized about 254 kg N ha-1 19 kg P ha-1, 181 kg K ha-1 56 kg Ca ha-1 and 28 kg P ha-1 over 18 months and became a transient pool that would recycle its nutrients at a later stage in the plantation life.

OPTICAL PROPERTIES FOR MECHANICAL HARVESTING OF OIL PALM FFB

WAN ISHAK WAN ISMAIL; MOHD ZOHAIDIE BARDAIE and ABDUL MALIK ABDUL HAMID

The engineering properties of agricultural materials constitute important engineering data in the design of machines to be used in harvesting. A colour camera vision system was developed to distinguish between different categories of oil palm fruit bunches. The maturity or colour ripening index was based on different colour intensity. Machine vision employs a computer and camera to analyse and interpret images equivalent to the human eye and brain. The colours namely red, green and blue (RGB) of the palm oil fruit bunch were investigated using camera vision. The specimens were captured using a CCD camera, Matrox Meteor card, and Matrox Intellicam software. The laboratory results showed that the ripe fruit bunch could be differentiated from other categories of fruit bunches based on RGB intensity. A computer program written was able to differentiate the ripe fruit bunch and send a signal to the controller to activate the machine or robot arm to carry out harvesting.

IDENTIFICATION OF FLOWER SPECIFIC PROTEINS IN THE OIL PALM (Elaeis guineensis) BY TWO-DIMENSIONAL GEL ELECTROPHORESIS 

RAJINDER SINGH and CHEAH, S C

Total RNA was isolated from young etiolated oil palm seedlings, leaves and inflorescences at different stages of development. The mRNA was subsequently extracted by oligo-dT cellulose chromatography and in vitro translated using a rabbit reticulocyte system. The translated products were examined by SDS-PAGE gel electrophoresis as well as a combination of SDS-PAGE and isoelectric focusing (two-dimensional polyacrylamide gel electrophoresis). Both methods revealed differences in banding pattern between the inflorescence (flower) and vegetative (leaf and young etiolated seedlings) tissues, indicating differential gene expression. Some changes were also observed in the pattern of in vitro translation products for mRNA extracted from the different stages of flowering.

DECOMPOSITION AND N & K RELEASE BY OIL PALM EMPTY FRUIT BUNCHES APPLIED UNDER MATURE PALMS 

LIM, K C and ZAHARAH, A R

The oil palm empty fruit bunch (EFB) is one of the major waste products of the oil palm industry and is currently used as an organic mulch in young and mature oil palm plantations. A field experiment was set up to monitor EFB decomposition and N and K release for a period of 10 months with the EFB placed in single or double layers stacked along mature oil palm interrows with and without inorganic N and K fertilizers. The quantity of EFB applied was 37.5 t ha-1 applied in a single layer and 75 t ha-1 applied in a double layer. N was applied as ammonium sulphate and K as muriate of potash at three rates of 0, 3.5 and 7.0 kg fertilizers palm-1 yr-1. The frequency of fertilizer application was once and three times per year. Random samplings of EFB were taken from the single layer, and from the top and bottom layer of the double layer treatment and dry weights, N and K concentrations determined..

The EFB dry matter loss followed an exponential model. There was a 50% loss in dry matter in the initial three months and 70% dry matter loss after eight months. The single layer EFB decomposed faster than the double layer top or bottom. Addition of inorganic N fertilizer enhanced significantly dry matter loss in the single layer EFB. Inorganic K fertilizer application did not significantly affect EFB decomposition for all treatments. Release of EFB-N was not detected during the 10-month period of the study. Release of EFB-K was very rapid during the initial stages of decomposition, with 90% of it released after six months of decomposition. At 10 months, more than 99% of EFB-K and been released.

STUDIES ON FACTORS AFFECTING THE COLOUR STABILITY OF SOME COMMERCIAL PALM FATTY ACIDS 

OOI, T L and YEONG, S K

The colour stability of some commercial palm fatty acids at 90°C, 110oC and 130ºC was investigated. The degree of whiteness of palm fatty acid started to decrease at 110ºC and rate in percentage of whiteness decreasing was faster at higher temperatures. The general order of colour stability of palm fatty acids to heat at 130ºC and 110ºC are respectively as below:
98% palmitic acid > double pressed > triple
pressed > single pressed > 70% strearic > 70%
oleic acid.
98% palmitic acid > 70% stearic acid > triple
pressed > double pressed > single pressed >
70% oleic acid.

The likely factors, viz. minor constituents and trace unsaturated acids, affecting the colour development were studied. Minor constituents were isolated from the various types of palm fatty acids and were found to consist mainly of straight chain hydrocarbons. The major hydrocarbons present in 70% oleic acid were tentatively identified as hydrocarbons C26H50 and C26 H52. The exact structures are yet to be identified. The minor components which affect the colour stability of palm fatty acid could be removed by silicic acid or citric acid treatments. Dimers of oleic acid-oleic acid and oleic acid linoleic acid were among the components identified in the yellow components fraction isolated from heated palm fatty acids which could be causing the yellow colour. The results indicated that the problem of colour stability of the palm fatty acids is rather complex and is mostly likely due to the presence of traces of unsaturated fatty acids and some unknown minor components in fatty acids.

VOLUME 12 NO. 1,June  2000

DIFFERENTIAL SCANNING THERMOGRAMS OF PALM OIL TRIGLYCERIDES IN THE PRESENCE OF DIGLYCERIDES

Siew, W L and Ng, W L.

The melting and crystallization behaviour of palm oil triglycerides was characterized by differential scanning calorimetry (DSC). The influence that diglycerides have on the melting and cooling behaviour of palm oil is dependent on the concentration and nature of diglycerides. All the diglycerides (PP,PO and OO) and the palm diglyceride mixture (PDG) depressed the melting point of the oil. The 1,2 isomer was more effective than the 1,3 isomer. An excess of 1,3 PP elevated the melting point. The crystallization behaviour is complicated if 1,3 PP is present in high concentrations. All the diglycerides studied can undergo co-crystallization with palm triglycerides, except for 1,3 PP at high concentration.

STUDIES TOWARDS UNDERSTANDING PROLINE ACCUMULATION IN OIL PALM (Elaeis guineensis Jacq.) POLYEMBRYOGENIC CULTURES

Tarmizi, A and Marziah, M

Thioproline (a proline analog) at 10 mM induced proline (PRO) accumulation in oil palm polyembryogenic (PE) cultures. However, this treatment eventually killed the cultures, presumably due to some degree of toxicity. PE cultures utilized the exogenous proline (ExoPro) and ornithine (ExoOrn) more efficiently in liquid medium than in solid medium. The Pro accumulating cultures which were treated with ExoPro, ExoOrn, or subjected to low temperature stress returned to normal levels on transfer to normal media and conditions. These reversible changes in cellular Pro concentration are consistent with Pro being readily utilizable and so it can be considered a labile metabolize in oil palm PE cultures.

VALUABLE MINOR CONSTITUENTS OF COMMERCIAL RED PALM OLEIN: CAROTENOIDS, VITAMIN E, UBIQUINONES AND STEROLS

Bonnie, T Y P And Choo, Y M

The important minor constituents of crude palm oil (CPO) - carotenoids, vitamin E, ubiquinones and sterols are also preserved in the commercial red palm olein (CRPo). The average carotene content was found to be about 665 ppm. The high-performance liguid chromatography (HPLC) profile of carotenoids showed that all the 11 types of carotenoids of CPO were preserved in CRPo, a - and b-carotene still constitute about 80% of the total carotenoids. Xanthophylls: dehydro-retinal, -caroten-dione and b-caroten-5,6-epoxide were also tentatively identified based on their UV spectra and elution order. The vitamin E content was in the range of 717-863 ppm, consisting of a-tocopherol (19%), a-tocotrienol (29%),  -tocotrienol (41%), and d-tocotrienol (10%).The sterol content is in the range of 325-365 ppm consisting of b-sitosterol (59%), campesterol (22%), stigmasterol (17%) and cholesterol (<2.6%). Coenzyme Q10 was detected in CRPo with a concentration range of 18-25 ppm. The fatty acid composition indicates that CRPo has 46.7% monounsaturated, 12.8% polyunsaturated and 40.5% saturated fats.
 

SOIL NUTRIENT DYNAMICS AND PALM GROWTH PERFORMANCE IN RELATION TO RESIDUE MANAGEMENT PRACTICES FOLLOWING REPLANTING OF OIL PALM PLANTATIONS

Khalid, H; Zin , Z Z And Anderson, J M

The Policy of zero burning practices for replanting of oil palm plantations is currently considered desirable since it avoids air and water pollution and may also enable the development of more economically sustainable practices based on nutrient supply from organic matter management. Under the standard zero burning practices, young palms are planted between widely-spaced windrows of residues from the old stands. This practice maximizes the spatial and temporal uncoupling between the release of nutrients from the decomposing residues and plant uptake. An improved understanding of the spatial and temporal patterns of nutrient release and plant uptake will enable better management of the synchrony between these processes and greater conservation of nutrients. Studies were carried out on the establishment and growth of young palms planted into the palm residues which were chopped, shredded or pulverized without additional inputs of inorganic fertilizer. The preliminary results of palm responses to the techniques established were impressive as a consequence of improving nutrient synchrony and the beneficial effects of organic mulching on soil properties to crop production. It is concluded that these methods of planting and residue management improved the spatial integration of nutrient release and uptake by the rooting systems of young palms. The supply of nutrient requirement that is partly provided by the recycling of biomass can reduce the use of inorganic fertilizers to optimize growth rates of the immature palms. Savings in fertilizers resulting from these practices could reduce the production costs as well as contributing towards environmental conservation.

DECOMPOSITION PROSSESES AND NUTRIENT RELEASE PATTERNS OF OIL PALM RESIDUES

Khalid, H; Zin , Z Z And Anderson, J M

The decomposition patterns of the oil palm residues were found to show a decreasing remaining of dry matter in the order: leaflets > rachises = trunks > roots. The leaflets reached t₅₀ at six months, the rachises and trunks at eight months and the roots at 10 months. The decomposition rate constant 'k' of the oil palm residues ranged from 0.13% to 0.22% day^-1 in which the leaflets, rachises, trunks and roots had a value of 0.22%, 0.17%, 0.17%, and 0.13% day^-1 respectively . The controls regulating decomposition of oil palm residues during the study period have been shown to operate in the rank order: macroclimate > microclimate > resource quality > organisms. Rainfall distribution was the main climatic factor that controlled the moisture content of residual materials and the microlimate within different locations in the residue piles strongly modified the variation in temperature and moisture that affected the rate of decomposition. On the everage, most of the oil palm residues were found to decompose within 12-18 months while some of the hardier materials, particularly roots, took much longer than 18 months to decompose. Significant accumulation of light organic carbon fraction on the soil surface will provide and relase nutrients to the soil.
 Nutrients released from oil palm residues showed different release patterns between residue types and nutrients. The leaflets, rachises, trunks and roots all showed nutrient release in the order: K>Mg=Ca>P>N. The release of nutrients from the residues was relatively quick, especially K, with more than 70% of the nutrients released. Generally, the release and transfer of nutrient to the soil pool occurred within the 18 months period.

PREPARATION AND CHARACTERIZATION OF ADSORBENTS FROM OIL PALM FRUIT SOLID WASTES

Guo, J And Lua, A C

Preparation and characterization of activated carbons from oil palm fruit solid wastes were studied. The effects of activation conditions (CO₂ flow rate, activation temperature and retention time) on the characteristics of the activated carbons, namely density, porosity, BET surface area, pore size distribution and surface chemistry were investigated. The optimum conditions for activation were an activation temperature of 800°C and a retention time of 30 min for fibre or 50 min for shell, which gave the maximum BET surface area. Adsorption tests showed that the activated carbons from oil palm fibre and shell could be used as adsorbents for both liquid-phase and gas-phase adsorption.

PERFORMANCE OF Elaeis Oleifera FROM PANAMA, COSTA RICA, COLOMBIA AND HONDURAS IN MALAYSIA

Mohd Din, A; Rajanaidu, N And Jalani, B S

The performance of Elaeis oleifera from Panama, Costa Rica, Colombia and Honduras was evaluated in a trial at PORIM Research Station, Kluang, Johor, Malaysia. FFB yield, bunch components, vegetative traits, fatty acid composition, iodine value ( I.V.) and total carotene were analysed. Among the oleifera progenies, the highest fresh fruit bunch (FFB) yield was 101.4 kg palm^-1 yr^-1, total oil to bunch (TOTB) was highest at 9.0%, height increment rate (HTI) lowest at 4.6 cm yr^-1, I.V. highest at 96.7 and total carotene highest at 3455.5 ppm. There were significant differences between the four countries for the yield components: average bunch weight (ABWT), parthenocarpic bunch component: mean fruit weight (MFW), oil to wet mesocarp (OTWM) and oil to bunch (OTB), fertile bunch components: MFW, mean nut weight (MNW) and shell to fruit (STF), vegetative traits: petiole cross section (PCS), rachis length (RL), leaflet length (LL), leaflet width (LW), height (HT) and leaf area (LA), component fatty acids: C14:0, C16:0, C16:1, C18:0, C18:1 and C18:2, I.V. and total carotene.

SYNTHESIS AND CHARACTERIZATION OF ESTER FROM DIHYDROXYSTEARIC ACID

Roila, A And Salmiah, A

The esterification of dihydroxystearic acid as a source of hydroxy fatty acid and monohydric fatty alcohols (C8-C18) was successfully carried out. The reaction was done at 180°C in the absence of catalyst and the yield of the ester obtained was 80%-96%. The products were analysed by infrared spectroscopy, and some of their physical properties determined.

OIL PALM SHELL AS A SOURCE OF PHENOL

Md Kawser, J And Farid Nasir, A

Oil palm shell was pyrolysed in an externally heated 5 cm diameter, 30 cm high fluidized-bed fast pyrolysis reactor with nitrogen as the fluidization gas and silica sand as the bed material. The products obtained were liquid oil, solid char and gas. The pyrolysis reactor bed temperature was maintained at 500°C with a fluidization gas flow rate of 1.26 m³ hr^-1 because this was found to be the optimum condition for maximum liquid product yield. The maximum liquid product was found to be 58 wt% of dry oil palm shell feed. The liquid was a single-phase product. The liquid was characterized by FT-IR, GC/FID and GC-MS for its detailed chemical composition. From the analyses, the liquid was found to contain a very high concentration of phenol and its derivatives, viz., cresol, catechol, guaiacols, syringol, eugenol: 43.3 wt% of total liquid oil. All these are considered to be very high-value chemicals from the point of view of value and price. Thus, an appropriate separation and extraction method is required to find out how to obtain these chemicals, especially phenol, from the pyrolysis oil.

GEL PERMEATION CHROMATOGRAPHIC CLEAN-UP OF ORGANOPHOSPHORUS PESTICIDE IN OIL MATRIX 

Ainie, K; Hamirin, K And Tan, Y A.

Liquid-liquid partition chromatography is widely used as a clean-up procedure for organophosphorus pesticides from various matrices. However, gel permeation is now increasingly used for multipesticides determination. This investigation evaluated the gel permeation chromatography(GPC) for clean-up of monocrotophos in an oil matrix. The gel used in this study was Bio-Beads SX-3 and the GPC solvent system cyclohexane:ethyl acetate (1:1 v/v). The analyte was determined in a gas chromatograph fitted with a flame photometric detector in the phosphorus mode. Recovery of monocrotophos was 74.3%-101.6% with a standard deviation of 3.409-13.453. The method is used for monitoring monocrotophos in edible oil.

FATTY ACYL SUBSTITUENT-INDUCED CHANGES IN 13C-CHEMICAL SHIFTS OF CARBONYL CARBONS: A TOOL FOR STRUCTURAL ELUCIDATION IN ACETYLATED GLUCOSE ESTERS OF PALM FATTY ACID

Olobo J Obaje; Dzulkefly Kuang; Hamdan Suhaimi; Anuar Kassim And Zaizi Desa

Substituent-induced changes (SIC) in ¹³C-chemical shifts of carbonyl carbon atoms upon interesterification of glucose pentaacetate (GPA) with fatty acid methyl esters (FAME) of stripped palm kernel oil (SPKO), palm oil (PO) and capric (C₁₀) acid, were used to determine the number and positions of the fatty acid substituents on the pyranosyl ring. Results show that SIC on the ring carbon and ring proton atoms are not always consistent with the molecular structures. But SIC on the carbonyl carbon atoms are however unambiquous and consistent with molecular structures of all the products. The analysis of ¹³C-chemical shift changes of carbonyl carbon therefore provides a means to determine the number and positions of fatty acyl groups in polyacetylated glucopyranoses.

SURFACE ACTIVE PROPERTIES OF PALM OIL WITH RESPECT TO THE PROCESSING OF PALM OIL

Chow, M C And Ho, C C.

The supernatant sludge from the palm oil mill was determined to be surface active from surface tension measurement. In crude palm oil (CPO)/ sludge supernatant, the interfacial tension was determined to be 3 mN m^-1 which is favourable for the formation of oil droplets in the CPO slurry.

The refined oil / water systems have higher interfacial tension compared to the CPO / water system. Depending on whether the CPO is chemically or physically refined, the oil/water interfacial tension differs and can be as high as 25.6mN m^-1 and 12.7mN m^-1 respectively compared to an interfacial tension of 8.00 mN m^-1 in the CPO/water system. The higher interfacial tension value indicates more efficient removel of surface active compounds from the chemically refined oil. This may have great implications in the quality and utilization of palm oil in food processing.

The interfacial tension values of the partially refined oils as sampled from various points of refining were found to increase as the oil is processed. In view of this increase, interfacial tension could possibly be used as a process control parameter in the refining of CPO.

Lecithin and monoglycerides were determined to significantly reduce the interfacial tension at the refined palm oil/ water interface. Some of the common minor constituents found in CPO such as carotene, diglycerides, fatty acids and cholesterol did not show surface activity at the refined palm oil /water interface.

PROPERTIES OF BIOSURFACTANT ENZYMATICALLY PREPARED FROM FRUCTOSE AND PALM FATTY ACID

Rakmi Abdul Rahman And Tjahjono Herawan

A biosurfactant has been successfully synthesized from fructose and palm fatty acid distillate (PFAD) with Lipozyme IM as biocatalyst. Analysis of its physical and chemical properties showed that this surfactant had a melting point of 49°C-52.3°C and a hydrophile-lipophile balance (HLP) of 16+. This HLB value is in the range suitable for use in cosmetics, detergents and foods. This surfactant, which was a fructose ester, also reduced the surface tension of water from 74 dynes cm^-1 to 38.3 dynes cm^-1.

MODELLING THE EFFECTS OF 'HAZE' ON OIL PALM PRODUCTIVITY AND YIELD. 

Henson , I E.

An increasing incidence of atmospheric pollution in the Southeast Asian region leading to substantial reductions in solar radiation has promoted concern over the possible long term effects on oil palm yields. Previous models of oil palm growth and production have emphasized the importance for yield of adequate radiation but effects of reduced radiation on yield are not immediately apparent due to the long time required for bunch morphogenesis, the complexity of the process and the presence of assimilate stores which serve to buffer the palm against periods of adverse conditions.

Because climatic factors other than radiation influence the physiological processes on which productivity is dependent, models were developed to take into account the other main factors, namely, temperature , atmospheric vapour pressure deficit (VPD) and soil water availability . Temperature had only a small effect because variations in mean temperature were small. Soil water availability had a larger influence but VPD was the most important factor influencing yields. A lower VPD, lower temperature and improved soil water supply associated with reduced radiation tended to offset yield reductions due to lower light intensity. Under certain conditions, predicted yields were higher under low or moderate than under high radiation. High radiation was associated with high evapotranspiration (ET) rates and lower rainfall, leading to increasing likelihood of soil water deficits and drought-induced yield reductions.

The results of the modeling exercise are related to palm performance in other regions with contrasting radiation receipts.