Category Archives: 2018 Vol 30 Dec

TRANSGENIC OIL PALM ANALYSIS VIA FLUORESCENCE in situ HYBRIDISATION, FLOW CYTOMETRY AND CYTOLOGICAL TECHNIQUES

Transgenic oil palm plantlets containing the transgenes, phaA, phaB and phaC responsible for the synthesis of polyhydroxybutyrate (PHB) were analysed using flow cytometry (FCM), cytological and fluorescence in situ hybridisation (FISH). Flow cytometry analysis was carried out to determine the nuclear DNA content of the transgenic oil palm. Analysis of the results showed significant differences between all the transgenic events and DxP regenerated plantlets (control). The mean genome size for DxP regenerants (2C = 3.52 ± 0.30 pg) was smaller compared with all the transgenic events, which had different genome sizes: TE 3-11 with size 2C = 4.38 ± 0.37 pg, TE 7-22 with 2C = 4.31 ± 0.26 pg, TE 4-5 with 2C = 4.09 ± 0.31 pg, TE 6-4 with 2C = 4.07 ± 0.63 pg, TE 9-4 with 2C = 4.01 ± 0.25 pg and TE 11-15 with 2C = 4.01 ± 0.37 pg. Cytological analysis showed no chromosomal aberrations such as anaphase bridges or lagging chromosomes. FISH analysis showed integration of transgenes on one or two chromosomes, targeting the distal region of long and middle length chromosomes.

COMPOSITION OF TERMITES IN THREE DIFFERENT SOIL TYPES ACROSS OIL PALM AGROECOSYSTEM REGIONS IN RIAU (Indonesia) AND JOHOR (Peninsular Malaysia)

Termites are perceived as decomposers and as pests in an ecosystem. A study on the species composition of termites in different soil types (i.e. clay, sand and peat) in oil palm plantations was conducted between 6 April 2015 and 10 December 2015 in nine selected localities in Johor (Malaysia) and Riau (Indonesia). Sampling of termites was conducted using belt transects of 100 m in length and 4 m in width in the oil palm plantation. A total of three replicates for each soil types were done from the nine transects for each location. A total of 41 species from five subfamilies (i.e. Coptotermitinae, Rhinotermitinae, Termitinae, Macrotermitinae and Nasutitemitinae) and two families (i.e. Rhinotermitidae and Termitidae) of termite species were successfully sampled and recorded. Sand soil (81 colonies: 12 species; four subfamilies; two families) recorded the highest colonies, followed by peat soil (62 colonies; 12 species; five subfamilies; two families), and clay soil (47 colonies consisting; nine species, four subfamilies and two families). There was a significant difference (χ2 = 618 886 df = 328, p<0.005) between soil types and termite species composition that were found in the oil palm plantation. This study identified that the diversity and abundance of termites differed between soil types in different oil palm plantations.

OPTIMISATION OF SQUALENE RECOVERY FROM PALM OIL BY-PRODUCT USING INTEGRATED SCCO2 -PRESSURE SWING

Squalene is used as an ingredient in functional foods, pharmaceuticals, and cosmetics. Due to the limitation of squalene availability from predominant source which is shark liver oil and to sustain the environment by fully utilising the by-product of palm oil, an effort has been made to find a potential source of squalene as an alternative to shark liver oil. The motivation for this work is to optimise its extraction from an alternative source, a palm oil by-product known as palm fatty acid distillate (PFAD), using supercritical carbon dioxide (sc-CO2 ) with the aid of a pressure swing technique. The measurements were performed using a sc-CO2 extraction in a fixed bed at temperatures of 40°C, 50°C, and 60°C, pressures of 20, 30 and 40 MPa, and holding times of 20, 30 and 40 min; high performance liquid chromatography (HPLC) was used for squalene content analysis, optimised with a central composite design using research surface methodology (RSM). The second-order polynomial mathematical model adequately fitted the experimental results. The maximum squalene content from the model was predicted to be 356.24 ppm under the set of conditions with pressure of 23 MPa, temperature at 40°C, and 20 min holding time.

PREDICTION OF SOLID FAT CONTENT CURVE OF CHEMICALLY INTERESTERIFIED BLENDS OF PALM STEARIN AND SOYABEAN OIL

Solid fat content (SFC) is a fundamental physico-chemical property of lipids. Common SFC determination methods are time-consuming and expensive. Here, regression models were used for description of the SFC of chemically interesterified palm stearin/soyabean oil blends as a function of fatty acid composition, temperature or both. Briefly, sigmoidal models described the SFC curves as a dependent variable of saturated fatty acids (SFA) very well [SFCf(SFA), R²>0.98, mean absolute error (MAE)<1.71%] or temperature [SFCf(T), R²>0.98, MAE<1.67%]. However, the Gompertz function predicted the SFCf(SFA) and SFCf(T) curves better than the other functions. Lastly, a Gompertz function describing SFC as a multiple function of both SFA and temperature [SFCf(T,SFA)] was developed, which could describe the experimental data with R2=0.98 and MAE=1.86%. Validation of the Gompertz SFCf(SFA) and SFCf(T,SFA) models confirmed their high ability in prediction of SFC of different interesterified fats made from fully hydrogenated soyabean oil, palm stearin or palm olein.

FORMULATION OF A LOW GLYCEMIC BINDER FORTIFIED WITH PALM VITAMIN E (tocotrienol-rich fraction) FOR FUNCTIONAL GRANOLA BARS

A granola bar is the combination of dry ingredients and a wet binder compressed into a bar form and is an excellent vehicle for delivering bioactive compounds to consumers. Sugar is one of the main components in granola bar binder, and it provides the sticky property and flavour to the granola bar. However, high sugar consumption can cause complications and health problems. This study focuses on the use of low glycemic natural sweeteners in the formulation of a granola bar binder and palm vitamin E (tocotrienol-rich fraction, TRF) as a potential fortifier to enhance the functionality of the granola bar while promoting health benefits, including cardioprotection, neuroprotection, as well as hypocholesterolemic, anti-cancer and antioxidant properties. An augmented simplex lattice design was used to develop the granola binder with natural low glycemic sweeteners (in response to °Brix), namely honey, date paste and coconut sugar. The desired °Brix was 80 to 85. The optimal range of sweeteners blend with the desired °Brix was 31.18% to 38.4% of honey, 7.25% to 9.43% of date paste and 24.65% to 32.63% of coconut sugar. Granola bars were prepared using three different sweetener formulations. Palm TRF was added to the selected binder formulation to enrich the vitamin E content in the finished product (granola bar). Honey and coconut sugar were responsible for the effect on °Brix of the binder, while date paste was the limiting factor that constrained °Brix. Granola bar with 15.22% honey, 4.71% date paste and 16.31% coconut sugar received sensory scoring which was significantly higher than for a commercial bar. The formulated granola bar which was enriched with 3.23 mg g-1 vitamin E had a proximate composition and caloric value comparable to that of the commercial granola bar.

OPTIMISATION OF ENZYMATIC DIRECTED INTERESTERIFICATION OF PALM OIL FOR HIGH YIELD OF TRIUNSATURATED TRIACYLGLYCEROL USING RESPONSE SURFACE METHODOLOGY

Unsaturated fatty acids (USAFA), especially monounsaturated fatty acids (MUFA), has been shown to provide substantial health benefits. This study attempted to increase the triunsaturated (U3 ) triacylglycerols (TAG) content in palm oil (PO) via lipase-catalysed directed interesterification (EDIE), to enable the production of a liquid fraction that is high in USAFA, especially MUFA. A response surface methodology with three factors and five levels in a central composite design was employed for optimisation of the EDIE conditions for the U3 TAG production. The effects of reaction temperature (20°C-50°C), reaction time (12-28 hr) and enzyme load (2%-18%) on the U3 TAG and by-products yields were investigated. Well-fitted quadratic and linear models were successfully established for both responses. All processing conditions affected significantly (p<0.05) U3 TAG yield. By-products yield was affected by reaction time and temperature. Although increasing reaction temperature and enzyme load, and extending the reaction time resulted in a higher U3 TAG yield, a higher amount of by-products were formed as well. The optimised processing conditions were a reaction temperature of 30°C and reaction time of 18 hr, when immobilised lipase enzyme load was set at 10% (w/w), and resulted in yields of about 27% of U3 TAG and 23% of by-products.

QUALITY SOFT TABLE MARGARINE WITH MINIMAL POST-CRYSTALLISATION THROUGH HIGH PRESSURE PIN-ROTOR UNIT

Post-crystallisation is a hardening phenomenon in margarine and shortening after production. The choice of oils and fats, diacylglycerol (DAG) content and processing are several ways identified that could overcome post-crystallisation problem. There have been studies to understand this phenomenon, through the effects of emulsion temperatures, throughput speed, tube-cooler temperatures and pin-worker speed. Post-crystallisation in non-hydrogenated margarine during storage is significantly related to processing. Thus, minimising the post-hardening problem in palm-based soft margarine by studying the performance of high pressure working unit of margarine pilot plant will be the objective of the current work. A formulation containing palm oil as the major oil and a soft oil with a balanced ratio of 1:1:1 in saturated, monounsaturated and polyunsaturated fatty acids was processed in a margarine pilot plant. For evaluating the effects of high pressure coupled with pin-rotor, a high-speed pin-rotor and a double stage homogeniser were installed. The oils and fats and the finished products were analysed for their fatty acid composition, solid fat content, texture and hardness value upon storage. Post-crystallisation was greatly minimised in the soft margarine with the maximum usage of non-hydrogenated palm oil formulation at controlled storage temperatures of 5°C, 10°C, 15°C and 20°C.

OXIDATIVE CHANGES IN REPEATEDLY HEATED VEGETABLE OILS

Thermal oxidation of vegetable oils due to repeat heating is known to exert adverse effects on human health. The oxidative stability of vegetable oils is one of the important factors in determining suitable types of cooking oils and cooking methods. Therefore, the oxidative changes in several types of commonly used vegetable oils, namely: palm olein (POo), soyabean oil (SBO) and corn oil (CNO) were studied. The oil samples were heated repeatedly at 150°C for five rounds. The oxidation level of the oils was assessed by determining their respective changes in fatty acid composition, peroxide value (PV), free fatty acid (FFA) value and p-anisidine value (AV). SBO and CNO contained significantly higher amount of unsaturated fatty acids (84.1% and 86.2%, respectively) compared to POo (56.8%). Consequently, PV, FFA and AV value of the oil samples increased according to their unsaturation level: POo < SBO < CNO. Therefore, POo was shown to have the greatest oxidative stability against thermal oxidation, followed by CNO and SBO.

OPTIMISATION OF PROCESS CONDITIONS FOR ETHANOL PRODUCTION FROM ENZYMATICALLY SACCHARIFIED EMPTY FRUIT BUNCH USING RESPONSE SURFACE METHODOLOGY (RSM)

Oil palm empty fruit bunch (EFB), being one of the lignocellulosic biomass forms generated from the palm oil milling process, has high contents of cellulose and hemicelluloses for bioethanol production. However, the conversion routes so far remain challenging and optimisation is necessary. This article aims at optimising the fermentable process variables in the production of bioethanol from EFB using response surface methodology (RSM). The EFB was firstly pre-treated with mild NaOH, then hydrolysed using diluted H2SO4 to extract mainly xylose and subjected to enzymatic saccharification for glucose recovery prior to fermenting the sugars with Saccharomyces cerevisiae. A Central Composite Design (CCD) was used to optimise the three independent variables involved i.e. pH, temperature and agitation rate. The RSM data subjected to analysis of variance (ANOVA) and a second-order polynomial model revealed the optimised conditions: pH 4, 30°C, 150 rpm and 72 hr in batch fermentation. The validation experiment under these conditions gave a maximum bioethanol yield of 0.66 g g-1 glucose, which was very close to the predicted value (0.56 g g-1). These results confirmed that the model was adequate and reliable to optimise bioethanol production from the enzymatically hydrolysed EFB.

COMPATIBILITY OF TERNE SHEET WITH PALM BIODIESEL BLENDS

The quality of biodiesel blends and its compatibility with fuel tank materials needs to be investigated before any higher biodiesel blends are introduced. This is to ensure that there are no leaching of any undesired materials which may degrade or oxidise the fuel and ultimately cause failure to vehicles. This article discusses the oxidation stability of palm biodiesel and its blends with petroleum diesel, i.e. B7, B10 and B15. The effect of palm biodiesel and its blends on terne sheet were examined using cup test. Terne sheet, a material commonly used to fabricate automotive fuel tanks, has been previously identified as incompatible with biodiesel. Nevertheless, the findings showed that palm biodiesel blends would not cause any corrosion or incompatibility with terne sheet. The terne plating was maintained at approximately 40 g m-2 after exposure to palm biodiesel and its blends at 80°C for 1000 hr. Scanning electron microscopy (SEM) morphologies have shown no signs of corrosion or pitting on the surface of the terne plating. No leaching of heavy metals was found on the fuel samples. Hence, the terne sheet was found compatible with palm biodiesel blends as long as the test fuels in use were of good quality.

MACROSCOPIC CHARACTERISTICS OF PALM OIL AND PALM OIL METHYL ESTER USING DIMENSIONLESS ANALYSIS

The spray characteristics of fuels greatly influence the emissions from diesel engines. Spray development plays a vital role in improving the combustion and emission characteristics of fuels because it directly affects the air-fuel mixture formation. The spray characteristics of fuels depend mainly on the fuel injection process, fuel density, fuel viscosity, ambient pressure, and temperature. Among these, the effect of fuel injection pressure and fuel viscosity is a very important parameter directly affecting spray structures. This study investigates the effects of viscosity of fuel on pre-heating. The spray characteristics such as spray angle and spray tip penetration in a constant volume chamber under non-evaporating conditions are carried out by Mie scattering techniques and using Image J software. The Weber number, Reynolds number, and air to fluid density ratio dimensionless numbers were used to capture the primary forces including the inertia, surface tension, and aerodynamics. The experiments were carried out for different pre-heat temperatures. For the fuels and temperature-pressure conditions evaluated, the Weber number varies from 3000 to 120 000, the Reynolds number varies from 10 000 to 63 000. The result of the macro analysis shows that an increase in the fuel temperature leads to a decrease in viscosity and density, thereby increasing the spray tip penetration.

EFFECT OF INJECTION TIMING ON PERFORMANCE AND EMISSION CHARACTERISTICS OF PALM BIODIESEL AND DIESEL BLENDS

Injection timing is a vital factor which governs the emissions and performance characteristics of the engine. This work portrays the effect of injection timing (IT) on cerium oxide nano particle doped palm biodiesel (20%vol) and diesel (80%vol) blends. Palm biodiesel is found to be a promising alternative to the petroleum diesel fuel owing to their similarity in physical and chemical properties. Addition of cerium oxide nano particle is carried out at 30 ppm, 60 ppm and 90 ppm. The modified fuels are introduced in reducing injection timing of 19°, 21° and 23° bTDC. A four-stroke, vertical, air-cooled, single cylinder, diesel engine is employed in this study. The performance characteristics (BSFC, BTE) improved for fuel blends at IT=23° bTDC. Further, results also revealed a significant reduction in emissions CO, NOX, HC emissions at IT=23° bTDC.

TOTAL PHENOLIC CONTENTS AND ANTIOXIDANT ACTIVITY OF PALM OILS AND PALM KERNEL OILS AT VARIOUS REFINING PROCESSES

Oil palm is one of the richest sources of antioxidants such as carotenoids, tocopherols, tocotrienols and phenolic compounds. This study quantified the amount of total phenolic content (TPC) and the antioxidant activity of crude to refined palm oil and palm kernel oil products obtained from palm oil mills. The TPC of the oil extracts was determined using Folin-Ciocalteau method expressed as gallic acid equivalent (GAE). Aqueous oil extraction with methanolic solvent was efficient and extract from crude palm oil (CPO) had the highest concentration of TPC. A reduction in trend was observed along the various stages of the refining steps probably due to losses through absorption of bleaching earth, volatilisation and degradation during the refining processes. The antioxidant activity was determined using 2,2-diphenyl-1-picrylhdrazyl (DPPH) assays. Results showed that the effect of antioxidants on DPPH radical scavenging activity decreases in the order of oil extracts CPO > CPKO > RPO > RPKO > RPOo > PKOo. Overall, it was found that CPO extract exhibited the highest antioxidant activity due to high TPC compared to other extracted oil samples.

IMPACTS OF WET AND DRY PERIODS ON LEAF GAS EXCHANGE, WATER USE EFFICIENCY AND CARBON ISOTOPE DISCRIMINATION IN DIFFERENT OIL PALM MATERIALS

This study was conducted to investigate the effects of two different periods (i.e wet and dry) and five different oil palm materials [i.e. tenera (DxP) and clonal palms (i.e. PL68, PL104, PL106 and PL127)] on leaf carbon isotope discrimination (Δ), leaf gas exchange parameters such as net photosynthesis (PN), stomatal conductance (gs ), transpiration rate (Tr ) ), intercellular CO2 concentration (ci) and instantaneous water use efficiency (WUE) and their relationships, in different oil palm materials cultivated on peat. Leaf gas exchange of 8-year old DxP and clonal palms were determined during dry and wet periods which were also analysed for leaf Δ. Results showed that there were significant differences in PN, gs and Tr between different periods. The gs values decreased by 54% during dry period compared to the wet period. This reduction in gs led to a reduction of 59% and 44% in PN and Tr , respectively. The interaction effect between oil palm materials and different periods had a significant influence on the leaf Δ values. Leaf Δ in clonal palm PL106 was less discriminated (23.74±0.42‰) compared to the D×P palm during dry season (27.92±0.70‰). A negative relationship was observed between leaf Δ with instantaneous WUE and leaf ∆ was found to be highly correlated with ci in oil palm during the wet period.

ENZYMATIC INTERESTERIFICATION OF PALM FRACTIONS FOR THE PRODUCTION OF COCOA BUTTER ALTERNATIVES – Review Article

Cocoa butter is the most preferable confectionery fat. In spite of this, cocoa butter alternatives (CBA) are also highly sought-after confectionery fats due to low supply and higher cost of cocoa butter. In the pursuit to produce palm-based CBA, various technological modification techniques have been employed. These include fractionation, blending, hydrogenation, interesterification (chemical and interesterification) or combination of these processes. Enzymatic interesterification (EIE) of lipids has received a lot of attention for the production of palm-based CBA especially cocoa butter equivalent. This review article, therefore, intends to offer an overview of EIE studies for the production of palm-based CBA. In this review, technological modification techniques are discussed in brief while publication related to EIE are discussed in depth based on its reactions categories (i.e. acidolysis, ester-ester exchange and alcoholysis). Reaction condition (i.e. subtrate, enzyme and optimum condition) and outcome of the EIE process are outlaid in this article.