Category Archives: InPress

IDENTIFICATION OF OIL PALM ROOT-SPECIFIC GENES THROUGH MINING OF RNA-SEQ DATA AND RT-qPCR ANALYSIS

Identification of novel genes that are specifically expressed in root is essential for isolation and characterisation of root-specific promoters. Mining the transcriptome of various oil palm tissue-specific data generated from ribonucleic acid-sequencing (RNA-Seq) technology has enabled the discovery of rootspecific genes. A total of seven candidates of root-specifically or preferentially expressed genes were selected from RNA-Seq analysis, and the gene expression profiles were validated using real-time quantitative polymerase chain reaction (RT-qPCR). The relative fold change of transcript expression in RT-qPCR was statistically analysed by comparing with root tissues at the in vitro culture stage (RS1). Results showed that the transcript annotated as an oil palm metallothionine (EgMT) gene was significantly upregulated at around 7 to 170-fold across the different developmental stages of root tissues. A proline-rich protein (EgPRP1) transcript was also significantly upregulated by about 7 to 55-fold. Both EgMT and EgPRP1 transcripts had relatively low expressions in the other tissues studied. The high levels of expression of EgMT and EgPRP1 in roots highlighted the genes’ promoter’s potential to regulate a strong expression level of transgenes in a root-specific manner.

PARAMETRIC STUDY ON TRASH SEPARATION EFFICIENCY IN FFB CONSIGNMENT

Trash or contamination in oil palm fresh fruit bunches (FFB) is one of the major problems encountered by palm oil millers. Trash is commonly referred to as non-oil palm fruit matters, such as stones, sand, soil, mud, wood, grass, leaves and twigs, which are constituted in FFB consignments delivered to the mills. Trash is undesirable as it often causes choking, severe process machinery wear and tear and reduction in oil extraction rate (OER) due to the inclusion of trash weight. In this study, a vibrating trash separating machine prototype was developed locally to separate undesirable trash from FFB consignments. This study aimed to evaluate the performance of this prototype machine based on the total amount of trash removed from the FFB and loose fruits consignments. Three gap size configurations were studied, namely 45, 30 and 15 mm. The results showed that the prototype machine successfully removed trash from wet and dry FFB consignments with separation efficiencies of 80.95% and 91.91%, respectively. The best gap size between the rod bars was indicated by 15 mm. This prototype machine is expected to solve the contamination issue during palm oil milling process due to lack of efficient system to remove trash from the FFB consignments.

PHYSICOCHEMICAL PROPERTIES OF PALM OLEIN-BASED POLYOLS PREPARED USING HOMOGENEOUS AND HETEROGENEOUS CATALYSTS

Research and development of palm-based polyols have been intensively carried out to improve their features and characteristics appropriate for their required applications. The physicochemical properties of palm olein-based polyols prepared using homogeneous (BF3.Et2O) and heterogeneous (K10 montmorillonite) catalysts in the ring-opening reaction of epoxidised palm olein (EPOo) were compared. Mono alcohols, i.e., methanol and isobutanol were selected as ring opening reagents. The formation of palm olein-based polyols was confirmed by the oxirane oxygen content (OOC), Fourier transformed infrared (FTIR) spectra and hydroxyl value (OHV) determinations. Based on the observation, the molecular weight (MW) of reagent used in the epoxide ring-opening reaction affected the viscosity of the obtained palm olein-based polyols. High oligomerisation was detected in palm olein-based polyol prepared using a homogeneous catalyst. The composition of hydroxyl monomer, dimer, trimer and tetramer in palm olein-based polyols were obtained from Gel Permeation Chromatography (GPC). Palm olein-based polyols prepared using heterogeneous catalyst exhibited the highest mono composition compared to other palm olein-based polyols. Heterogeneous catalyst provided palm olein-based polyols with low viscosity, less oligomerisation and functionality close to theoretical as compared to homogeneous catalyst. This finding can be used as a guideline in the synthesis of polyols with desired properties for targeted applications.

PUBLIC ENGAGEMENT PROMOTES CONSUMER CHOICE IN FAVOUR OF SUSTAINABLE PALM OIL

Despite the superior productivity, utility and economic benefits of palm oil compared with other oil crops, the palm oil industry often receives negative publicity for its environmental impact and there is widespread confusion over the perception of palm oil. The fact is that it is difficult to avoid palm oil consumption, and consumer boycotts will do little to resolve the social and environmental issues associated with oil palm agriculture. Instead, greater awareness of the importance of certified sustainable palm oil (CSPO) is needed. We used a mixed-methods survey to explore public awareness of palm oil, and understand the factors influencing sustainable consumer choice. Our survey, conducted in the Rainforest Biome of the worldrenowned Eden Project in the United Kingdom, a nation with relatively high environmental awareness, revealed that public awareness of palm oil was generally low and that consumers had poor knowledge of CSPO. We identified that the most significant barriers preventing consumer choice for CSPO products were unclear labelling, product availability and cost. We recommend that the palm oil industry focus on enhancing sustainability, promoting the benefits and increasing the visibility of CSPO in supply chains and final products, rather than waiting for consumer choice alone to drive change.

SYNTHESIS AND PHYSICOCHEMICAL PROPERTIES OF NEW ESTOLIDE ESTERS AS POTENTIAL BIOLUBRICANT BASE OIL

In this study, plant oil-derived oleic acid was modified chemically to generate estolide esters that displayed low pour points and good oxidation stability. Specifically, oleic acid was reacted with hydrogen peroxide (H2O2) to yield estolide with hydroxyl groups, which were then end-capped with various organic acids of different chain lengths and structures, while the carboxylic acid group of estolide was esterified with 2-ethylhexanol (2EH). Analysis results revealed that products end-capped with lauric acid (C12) and 2-ethylhexanoic acid, respectively recorded the best pour point at -36°C, while other products made with shorter or longer chain length organic acids showed higher pour points. Additionally, product end-capped with longer chain length organic acid exhibited better anti-wear properties and lower kinematic viscosity than product made with shorter chain length organic acid. Furthermore, the oxidation stability of products end-capped with linear organic acid were higher than those end-capped with branched organic acids and the oxidation onset temperature (OOT) of products were between 193°C-200°C, which is an improvement in comparison with starting material. Physicochemical properties evaluation revealed that most of the prepared estolides esters have lubricant properties comparable to commercial product, which suggested that they are suitable to be used as base oil for lubricants.

ASSOCIATION OF SEED COLOUR WITH GERMINATION, PHYSICAL AND PHYSIOLOGICAL GROWTH OF OIL PALM (Elaeis guineensis) SEEDLINGS

In commercial Dura x Pisifera (DxP) seed production, white-coloured seeds are perceived as abnormal despite lack of scientific evidence to support this. This study evaluates different seed colour (black, semiwhite and white) during germination and nursery evaluation. Four replications of 10 seeds were used for the evaluation of seed characteristic. Seed germination was conducted using four replications of 100 seeds by subjecting the seeds to 60 days of heat-treatment followed by germination at 30ºC. Thirty pre-germinated DxP seeds per replication were then transferred into the nursery for morphological, physiological and growth assessment at three months interval until 12 months after sowing. Germination test shows all seed types indicated similar germination percentage (more than 78%) and speed (13-15 days of mean germination time). Nursery assessment shows black seed indicated higher overall biomass within the first three months, however, no differences in growth were observed from six until 12 months after sowing. Physiological evaluation including net photosynthesis (5.3-18.13 µmol CO2 m–2 s–1), stomatal conductance and transpiration rate were similar among the seedlings produced by seeds differing in colour. Hence, seed colour does not implicate abnormality and should not be discarded for the purpose of seed production.

GROWTH AND DEVELOPMENT OF OIL PALM CLONE P164 EXPOSED TO LONGTERM CARBON DIOXIDE ENRICHMENT IN OPEN TOP CHAMBER

The carbon dioxide (CO2) enrichment study on oil palm clone P164 using open top chamber (OTC) technique was conducted to evaluate the effects on oil palm growth, physiology, bunch production and oil quality. The palms were grown in OTC with two CO2 concentrations; 600 ppm (CO2-enriched) and ambient 400 ppm (control), and also planted in the field under normal conditions (absolute control). After six years of observation, CO2-enriched palms showed a higher biomass percentage of 22.6% and 23.7% than the control and absolute control palms, respectively. The increase in biomass was contributed by rachis length and trunk height with a reading of 689.63 ± 7.70 cm and 201.25 ± 10.18 cm, respectively. This positive growth can be attributed to higher photosynthetic rate (A) of 23.51 ± 0.57 μmol m–2 s–1 and affecting the water use efficiency (WUE) of 5.33 ± 0.10 μmol mol–1 CO2. Enhanced A due to high CO2 level markedly increased clonal palm growth and biomass. Valuable information of this study may be beneficial for the oil palm industry to develop suitable mitigation strategies in the future

ASSESSMENT OF TRANS FATTY ACID LEVELS IN REFINED PALM-BASED OILS AND COMMERCIAL VEGETABLE OILS IN THE MALAYSIAN MARKET

Trans fats consumption is a major concern worldwide due to the deleterious effects associated with increased risks of coronary heart disease. The trans fatty acid (TFA) content of 104 refinery and commercial vegetable oils in the Malaysian market were analysed by gas chromatography. TFA levels in 29 samples of refined, bleached and deodourised palm oil, palm olein, palm stearin and palm kernel olein from palm oil refineries ranged from 0.12 ± 0.00 to 0.84 ± 0.01 g/100 g. Commercially packaged vegetable oils namely palm olein, sunflower, corn, coconut, rice bran, peanut, olive and sesame oils contained less than 1 g TFA/100 g while higher TFA levels ranging from 1 to 3 g/100 g were detected in canola oil, soyabean oil and canola-based oil blend samples. Amongst the premium oils, cold pressed unrefined almond and walnut oils were found to contain TFA levels exceeding 2 g/100 g while other oils in this category contained TFA less than 1 g/100 g. All retail palm-based vegetable oils and palm-based vegetable fat shortenings except for three samples conformed to the conditions for nutrition claims of low TFA of 1.5 g/100 g and 0.75 g/100 ml in both solids and liquids, respectively, as regulated in the Malaysian Food Act 1983.

INHIBITION OF CHOLINESTERASES BY WATER-SOLUBLE PALM FRUIT EXTRACT

Cholinesterase (ChE) inhibitors are used for the symptomatic treatment of Alzheimer’s disease and other neurological pathologies. There is interest in developing new ChE inhibitors from natural plant compounds. Water-soluble palm fruit extract (WSPFE) recovered from the aqueous oil palm vegetation liquor is rich in phenolic acids and has potential neuroprotective effects. Here, we investigated the effects of WSPFE samples on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). WSPFE ethyl acetate fraction (EAF) inhibited these enzymes the most (AChE IC50: 0.218 ± 0.029 μg ml–1; BChE IC50: 222.860 ± 5.777 μg ml–1) and had the highest AChE selectivity index (SI) value (1022.294) compared to whole samples and seven individual fractions but these effects were weaker than those of the AChE selective agent donepezil hydrochloride (DH) (AChE IC50: 0.013 ± 0.001 μg ml–1; BChE IC50: 19.820 ± 1.415 μg ml–1; AChE SI: 1524.615). Fractions containing p-hydroxybenzoic acid and protocatechuic acid had the lowest AChE SI values (7.584 and 9.367 respectively) and may thus, function as dual ChE inhibitors. Binary mixtures of DH and WSPFE EAF might have more potent inhibitory effects against these enzymes, as well as higher BChE/AChE selectivity. Further studies to investigate the ChE inhibition potential of these WSPFE samples are warranted.

THE COLD FLOW PROPERTIES OF PALM BIODIESEL FOR DIESEL BLENDS MANDATE IN MALAYSIA’S HIGHLANDS

Greenhouse gas emission from burnt fossil fuels in transportation leads to global warming. Therefore, biodiesel which is believed to help in reducing carbon dioxide (CO2) emission has been widely used as renewable energy that will replace diesel fuel. Biodiesel of 7% in diesel or B7 has been accepted worldwide to be the automotive fuel. In the last decade, most countries that implemented biodiesel program have gradually increased its biodiesel blending ratio above 7% for economic and environmental reasons. Malaysia has also announced the implementation of B20 starting January 2020. However, the biodiesel mandate in Malaysia’s highlands was maintained at B7 because of the concern on low temperature vehicle operability. This study focuses on the cold flow properties of the blended diesel fuels and the quality of the palm biodiesel for the national biodiesel program. The monoglycerides and the water content in the biodiesel were evaluated in relation to cold temperature fuel performance. Cloud point (CP) and cold filter plugging point (CFPP) of B7 diesel sold at highlands were found below the lowest ambient temperature recorded at highlands for the past 10 years. Both CP and CFPP of Euro 5 diesel were lower than Euro 2M diesel. A 41-months survey of the monoglycerides and the water contents in the palm biodiesel indicated that the palm biodiesel used in Malaysia’s biodiesel mandate meets both the EN14214:2019 and the Malaysian Standard MS2008:2014 specifications. CP and CFPP of the blended fuels increase with the increase of biodiesel blending ratio. Based on the study, it is anticipated that B20 could be introduced at Malaysia’s highlands without any problem.

CORRELATION BETWEEN NON-RIBOSOMAL PEPTIDE SYNTHETASE (NRPS) PRODUCTION AND VIRULENCE OF Ganoderma boninense PER71 ON OIL PALM (Elaeis guineensis)

Basal stem rot (BSR) disease caused by the white rot fungus Ganoderma boninense is the most destructive oil palm disease leading to production losses in fresh fruit bunches. Non-ribosomal peptide synthetase (NRPS) plays an important role in fungal pathogenicity. These large multi-modular enzymes catalyse the biosynthesis of secondary metabolites that act as fungal virulence factors. In this study, the detection of NRPS in G. boninense was achieved using polymerase chain reaction (PCR)-based method. Core motifs of adenylation domain of NRPS gene was identified in G. boninense. The deduced amino acid sequence showed similarity to the conserved core motifs (A2, A3 and A5) of the adenylation domain. Siderophores were predicted as the potential secondary metabolites synthesised by NRPS. Expression analysis of GbNRPS in 3-month-old oil palm artificially infected with G. boninense has confirmed the upregulation of GbNRPS at 1 month after inoculation (MAI) peaking at 4 MAI in susceptible clone but not in tolerant clone. There was a correlation between GbNRPS gene expression and disease severity. Susceptible clones showed significantly higher disease severity index (DSI) (62.50%) compared to tolerant clones (28.13%) at 4 MAI. This is the first putative detection of adenylation domain of NRPS (GbNRPS) gene and functional analysis of NRPS as a virulence factor in disease development.

STABILITY AND PERFORMANCE OF PALMBASED TRANSPARENT SOAP WITH OIL PALM LEAVES EXTRACT

Oil palm leaves (OPAL) is one of the oil palm waste components that can be extracted for natural phenolics. The OPAL extracts have been successfully extracted via four different extraction procedures; extraction with ethanol (OPAL M1), deoiled and followed by extraction with ethanol (OPAL M2), deoiled and extraction with ethanolic hydrochloric acid (OPAL M3) and aqueous extraction (OPAL M4). In this study, pH, moisture content, hardness, foaming power and stability, antioxidant activity and colour stability of transparent soaps with OPAL extracts were carried out. The results indicated that all transparent soaps with OPAL extracts had similar pH in the range of 9.88 to 9.98. However, there was a significant reduction of moisture content (14.6%-16.7%) compared to transparent soap control (18.3%) due to the evaporation of water during the melting and mixing. The hardness of transparent soaps with OPAL M3 and OPAL M4 was found to be softer than transparent soaps with OPAL M1 and OPAL M2. By adding OPAL extracts, the foaming ability and stability were not affected. Transparent soap formulated with OPAL M1 extract exhibited the highest percentage of antioxidant activity (3.7%). The use of OPAL extracts is recommended in transparent soap as it provides natural colourant.

EFFECT OF BIOFUEL ON LIGHT-DUTY VEHICLES ENGINE PERFORMANCE AND LUBE OIL DEGRADATION

Biofuel is a renewable, biodegradable and non-toxic fuel that is an alternative to fossil fuel. However, the long-term effect of biodiesel on internal combustion engine operation is not extensively studied. Thus, this study examined the effect of B5 biofuel (blend of 5% refined, bleached and deodourised palm olein oil (RBDPOo) and 95% automotive diesel oil (ADO) on engine performance and lube oil degradation of lightduty vehicles, i.e. Mercedes Benz (M), Mitsubishi Storm (MS) and Toyota Hilux (TH), up to 80 000 km mileage. ADO was also used for each vehicle brand for comparison. The engine power and torque were examined using chassis dynamometer. Analysis on wear metal content of lube oil was conducted to indicate engine deterioration level. Results showed insignificant deterioration on engine performance of M and MS vehicles using ADO and B5 but B5 vehicles showed lower torque reduction than ADO vehicles. For lube oil analysis, the properties and wear metal contents in B5 vehicles were within acceptable limit as suggested by the International Council on Combustion Engines (CIMAC). Results of this study concluded that the B5 biofuel can be potentially used for selected vehicle brands without engine modifications and normal service intervals can be applied for B5 vehicles.

HISTONE MODIFICATION MARKS IMPROVE IDENTIFICATION OF OIL PALM TRANSCRIPTION START SITES

Epigenetic regulation involves modifications of chromatin components such as post-translational modifications of histone proteins, methylation of cytosines in deoxyribonucleic acid (DNA), the involvement of small RNA and chromatin remodeling. Numerous methods have been established to understand the epigenetic control of agronomically important traits. Chromatin immunoprecipitation with sequencing (ChIP-Seq) is widely used to identify the binding sites of transcription factors or modified histones on a genome-wide scale. Here, ChIP-Seq targeting H3K4me3 and H3K27me3 marks in oil palm spears were conducted to examine genomic regions enriched with these histone modifications. Due to low DNA amounts from ChIP experiments, the data analysis workflow was optimised based on ChIP-Seq workflows on other plants. Mapping to specific target regions revealed that the histone mark peak positions were located close to predicted transcription start sites (TSS). This agrees with H3K4me3 and H3K27me3 profiles in other plants where H3K4me3 marks are generally associated with active genes and promoter regions while H3K27me3 marks are linked to repressed genes. Gene-wide mapping for low coverage ChIP-Seq data showed that H3K4me3 and H3K27me3 profiles on the oil palm genome corresponded to consensus histone profiles in other plants. This is the first ChIP-Seq analysis workflow reported for oil palm spears, which can be used to develop future oil palm ChIP-Seq studies.

NUTRIENT ENHANCEMENT OF PALM KERNEL CAKE VIA SOLID STATE FERMENTATION BY LOCALLY ISOLATED Rhizopus oryzae ME01

Palm kernel cake (PKC) is abundantly generated in palm kernel crushing plant throughout the year. Its use as monogastric animal food source is very limited due to its high fibre and moderate protein content. Therefore, this study is aimed to enhance PKC nutritional value, particularly the protein content through solid state fermentation (SSF), using a locally isolated fungus. Fungal identification was performed using partial 18S ribosomal ribonucleic acid (rRNA) nucleotide sequence. A fungus containing 600 base pairs was sequenced and aligned with GenBank database and named Rhizopus oryzae ME01. SSF was carried out using palm kernel expeller (PKE) which is mechanical pressed and palm kernel cake (PKC) which is solvent extracted, as a single carbon source with minimum mineral addition. Results showed that SSF successfully increased crude protein and ash content of fermented PKC and PKE, respectively. Interestingly, this study also found that the size of PKC’s particle had impacted protein content of fermented palm kernel cake (fPKC) during SSF. PKC which has a smaller and uniform size than PKE, gave higher crude protein increment than fermented palm kernel expeller (fPKE). However, the protein content of fPKE had increased by 7.64% more than fPKC which was only 3.45%. Thus, fPKE appeared to enhance PKE’s nutrient value, especially for monogastric animal feed applications.

DOES PALM MID FRACTION AFFECT ADULT SATIETY?

Dietary fats with different melting characteristics, fatty acids chain length and positional distribution may affect postprandial gut hormones and satiety response. We investigated the effects of palm mid fraction (PMF) (POP-rich), shea stearin (SS) (SOS-rich) and high oleic sunflower oil (HOSF) (OOO-rich) with either palmitic, stearic or oleic acid predominance at the sn-1 and sn-3 positions on gut hormone concentrations and satiety. A randomised, double-blind crossover (3 × 3 arms) orthogonal Latin-square study was conducted on 36 healthy adults (18 males, 18 females; average aged 23 years). Each subject received ~50 g of test fat incorporated in a muffin in random order, two weeks apart, over a six-week period. Blood samples were collected for a 3-hr period. We found that PMF- and HOSF-rich diets with either palmitic or oleic acid at the sn-1 and sn-3 positions exerted significantly higher (P<0.05) postprandial glucose dependent insulinotropic polypeptide (GIP) compared to SS-rich diet. However, plasma glucagon like-peptide 1 (GLP-1), peptide YY (PYY), ghrelin and visual analogue scale (VAS) (P>0.05) were not affected. These results suggested that PMF- and HOSF-rich diets increased the secretion of GIP that may promote satiety response in human adults.

SHORT COMMUNICATION: SIMPLIFIED APPROACH FOR EARLY IDENTIFICATION OF SPONTANEOUS OIL PALM HAPLOID (Elaeis guineensis)

Haploid technology facilitates the production of completely homozygous plants that are desirable in crop breeding. Having just one complete set of chromosomes in a haploid individual allows it to be doubled to produce a normal but pure 2n diploid plant. Here, we report a simple way to identify natural haploids of oil palm (Elaeis guineensis Jacq.) from screening 6400 abnormal germinated seeds. Initially, the germinated seeds were selected based on 12 unique ‘off-type’ morphological characteristics. The selected seeds were then grown and the seedlings were subjected to a second selection for three distinctive characteristics. Ploidy analysis with flow cytometry (FCM) and chromosome karyotyping confirmed the haploidy of one seedling with stunted height and size. Further analysis with the True-to-Type single nucleotide polymorphism (SNP) panel demonstrated that the plant was homozygous at all the loci tested, confirming its haploid status. This study has established a simple and systematic strategy that assists in accelerating early identification of oil palm spontaneous haploid.

MORPHO-PHYSIOLOGICAL ASSESSMENT OF OIL PALM (Elaeis guineensis Jacq.) SEEDLINGS EXPOSED TO SIMULATED DROUGHT CONDITIONS

Elaeis guineensis Jacq. (oil palm) production is threatened by drought due to climate change and anthropogenic deforestation. This study aims to understand how drought conditions contribute to changes in foliar nitrate-nitrogen concentration as well as the effects on the growth and development of oil palm seedlings. Seventy oil palm seedlings were maintained in a screen house and subjected to simulated drought conditions. There was a significant reduction in the number of leaves with increased drought exposure from 10 to four per plant. Oil palm leaves exposed to higher drought levels had less broad leaves, with leaf area ranging from 133.25-172.22 cm2 compared to the control (383.73 cm2). The foliar yield per plant was low in plants exposed to extreme drought condition (2.27 g), compared to 71.98 g in the control. Moreover, total drought-exposed oil palm seedlings had the highest concentration of nitrate-nitrogen. E. guineensis exposed to no-drought conditions had more roots (18 roots) than those exposed to total or partial drought (6-10 roots per plant). Overall, there was a decrease in height, leaf area and the number of leaves for most of the seedlings exposed to drought condition, which might be detrimental to their photosynthetic ability and growth.

BIRD SPECIES RICHNESS, ABUNDANCE AND THEIR FEEDING GUILD ACROSS OIL PALMS DEVELOPMENT THROUGH MIST-NETTING METHOD IN BETONG, SARAWAK

There are a lot of studies comparing birds in oil palm plantation with forests and other crop ecosystems but less on bird across drained peat swamp forest converted to oil palm plantation. This study assessed the bird species richness, abundance and their feeding guild change throughout the oil palm development phases including drained peat swamp forest (DPSF), cleared land (CL), one-year-old palm (1YOP), two-year-old palm (2YOP), three-year-old palm (3YOP), four-year-old palm (4YOP) and five-year-old palm (5YOP). Sixty-seven species of bird were recorded across the development phases through mist-netting method, of which 35.8% were only recorded in DPSF, 19.4% of the DPSF bird species continued to be recorded after the forest conversion to oil palm plantation, and 44.8% of bird species were additional species from DPSF species, appearing following the planting of oil palm. Species richness of bird was significantly higher in DPSF than CL but similar level to those in oil palm plantation. Even though level of species richness in oil palm plantation was similar level to those in DPSF, Non-metric Multidimensional Scaling revealed that bird compositions were different according to the three grouping habitats; DPSF, CL and oil palm plantation. Species richness of insectivorous guild was ranked higher along the oil palm development phases. Species abundance of insectivorous was ranked higher at the early stage of development then omnivorous guild recorded abundant once the Yellow-vented Bulbul started to dominate oil palm of more than 2YOP. Good understanding on bird’s distribution change across the conversion of forest to oil palm development gives a better idea on how to minimise land disturbance during plantation operations.

THE EFFECTS OF RECYCLING PALM PRESSEDFIBRE OIL ON CRUDE PALM OIL QUALITY

Palm pressed-fibre oil (PPFO) is known as a phytonutrients rich oil. PPFO was practically recycled back to the crude palm oil (CPO) processing line to increase oil extraction rates. This study evaluated the effect of blending CPO with PPFO at different PPFO dosage from 5%-25% (w/w) on blended oil quality. Free fatty acid (FFA) of blended oils increased from 3.42%-3.91%, while deterioration of bleachability index (DOBI) and iodine value (IV) decreased from 2.76 to 2.33 and 51.96 ± 0.37 to 50.21 ± 0.03, respectively. Minor components amount in blended oils were found to increase with carotenoids (539-654 ppm), squalene (475- 1201 ppm), sterols (433-808 ppm), phospholipids (34.67-63.84 ppm) and vitamin E (1185-1626 ppm). The oxidative stability of blended oils was improved (14.31-16.76 hr) but chlorine, iron and copper content were found to increase from 3.85-7.49 ppm, 13.58-17.63 ppm and 0.19-0.38 ppm, respectively. Although blending PPFO would deteriorate some quality properties of CPO, nonetheless, PPFO is rich with phytonutrients, therefore signifying its potential applications in pharmaceuticals and food industry.