Palm oil is an excellent choice for food manufacturers because of its nutritional benefits and versatility. The oil is highly structured to contain predominantly oleic acid at the sn2-position in the major triacylglycerols to account for the beneficial effects described in numerous nutritional studies. Oil quality and nutritional benefits have been assured for the variety of foods that can be manufactured from the oil directly or from blends with other oils while remaining trans-free. The oxidative stability coupled with the cost-effectiveness is unparalleled among cholesterol-free oils, and these values can be extended to blends of polyunsaturated oils to provide long shelf-life. Presently the supply of genetic-modification-free palm oil is assured at economic prices, since the oil palm is a perennial crop with unparalleled productivity. Numerous studies have confirmed the nutritional value of palm oil as a result of the high monounsaturation at the crucial 2-position of the oil's triacylglycerols, making the oil as healthful as olive oil. It is now recognized that the contribution of dietary fats to blood lipids and cholesterol modulation is a consequence of the digestion, absorption, and metabolism of the fats. Lipolytic hydrolysis of palm oil glycerides containing predominantly oleic acid at the 2 position and palmitic and stearic acids at the 1 and 3 positions allows for the ready absorption of the 2-monoacrylglycerols while the saturated free fatty acids remain poorly absorbed. Dietary palm oil in balanced diets generally reduced blood cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides while raising the high-density lipoprotein (HDL) cholesterol. Improved lipoprotein(a) and apo-A1 levels were also demonstrated from palm oil diets; an important benefits also comes from the lowering of blood triglycerides (or reduced fat storage) as compared with those from polyunsaturated fat diets. Virgin palm oil also provides carotenes apart from tocotrienols and tocopherols that have been shown to be powerful antioxidants and potential mediators of cellular functions. These compounds can be antithrombotic, cause an increase of the prostacyclin/thromboxane ratio, reduce restenosis, and inhibit HMG-CoA-reductase (thus reducing) cholesterol biosynthesis). Red palm oil is a rich source of beta-carotene as well as of alpha-tocopherol and tocotrienols.
The influence of sonoluminescence transesterification on biodiesel physicochemical properties was investigated and the results were compared to those of traditional mechanical stirring. This study was conducted to identify the mechanistic features of ultrasonication by coupling statistical analysis of the experiments into the simulation of cavitation bubble. Different combinations of operational variables were employed for alkali-catalysis transesterification of palm oil. The experimental results showed that transesterification with ultrasound irradiation could change the biodiesel density by about 0.3kg/m(3); the viscosity by 0.12mm(2)/s; the pour point by about 1-2°C and the flash point by 5°C compared to the traditional method. Furthermore, 93.84% of yield with alcohol to oil molar ratio of 6:1 could be achieved through ultrasound assisted transesterification within only 20min. However, only 89.09% of reaction yield was obtained by traditional macro mixing/heating under the same condition. Based on the simulated oscillation velocity value, the cavitation phenomenon significantly contributed to generation of fine micro emulsion and was able to overcome mass transfer restriction. It was found that the sonoluminescence bubbles reached the temperature of 758-713K, pressure of 235.5-159.55bar, oscillation velocity of 3.5-6.5cm/s, and equilibrium radius of 17.9-13.7 times greater than its initial size under the ambient temperature of 50-64°C at the moment of collapse. This showed that the sonoluminescence bubbles were in the condition in which the decomposition phenomena were activated and the reaction rate was accelerated together with a change in the biodiesel properties.
The influence of reaction temperature (160-200°C), residence time (45-90min), and liquid-solid ratio (8-16v/w) on oil palm frond (OPF) pre-treated with hot compressed water (HCW) was evaluated using severity factors. Effect of the process parameters studied on pulps composition and digestibility were found to be complex. The results revealed that digestibility could not be predicted merely according to composition. Severity factor was correlated with compositional changes and digestibility with good R-squared values at varied liquid-solid ratios (8-16v/w), but not with overall glucose yield. HCW pretreatment significantly improved the overall glucose yield up to 83.72% with severity of 3.31 and liquid-solid ratio of 8.0 compared to untreated raw OPF which only recorded an overall glucose yield of 30.97%. HCW is therefore an effective method for pretreatment of OPF for glucose recovery.
In order to evaluate the frying performance of palm-based solid frying shortening against standard olein, the fresh potato chips were fried in both frying media using an open fryer. After frying the chips for 40 h in an open batch fryer, it was found that the frying quality of palm-based solid frying shortening was better than standard palm olein in terms of Free Fatty Acid (FFA) values, Total Polar Content (TPC) and Total Polymeric Material (TPM). Solid shortening gave FFA, TPC and TPM values of 0.7, 15.3 and 2.67%, respectively, whilst standard palm olein gave values for FFA, TPC and TPM of 1.2, 19.6 and 3.10%, respectively. In terms of sensory mean scores, sensory panelists preferred the color of potato chips fried in solid shortening on the first day of frying, while on the third and fifth day of frying there were no significant differences (p < 0.05) in the sensory scores of fried products in both frying mediums. However, on the fifth day of frying, panelists gave higher scores in terms of taste, flavor and crispness for potato chips fried in solid shortening. These findings show that the palm-based solid shortening is better than palm olein when used for deep fat frying in terms of FFA values, total polar content and total polymeric material, especially for starch-based products such as potato chips. The result also shows that, in terms of sensory mean scores, after frying for 40 h, the sensory panelists gave higher scores in terms of taste, flavor and crispiness for potato chips fried in palm-based solid shortening.
Some unidentified minor compounds have been observed in the residue from short-path distillation of transesterified palm oil that are not detected in the original palm oil. A method combining short-path distillation to enrich the unknowns with fractionation using solid-phase extraction is described. The fractionated components were identified using GC coupled with MS. The transesterified palm oil was found to contain methyl esters of up to C32 carbon atoms. In the very long chain FAME with carbon numbers > or = 20, both even and odd carbon numbers accounted for 0.26 wt%, with C24 and C26 being the major ones present in the residue after short-path distillation of transesterified palm oil.
Chemical interesterification of rubber seed oil has been investigated for four different designed orifice devices in a pilot scale hydrodynamic cavitation (HC) system. Upstream pressure within 1-3.5bar induced cavities to intensify the process. An optimal orifice plate geometry was considered as plate with 1mm dia hole having 21 holes at 3bar inlet pressure. The optimisation results of interesterification were revealed by response surface methodology; methyl acetate to oil molar ratio of 14:1, catalyst amount of 0.75wt.% and reaction time of 20min at 50°C. HC is compared to mechanical stirring (MS) at optimised values. The reaction rate constant and the frequency factor of HC were 3.4-fold shorter and 3.2-fold higher than MS. The interesterified product was characterised by following EN 14214 and ASTM D 6751 international standards.
Due to its environment-friendly and replenishable characteristics, biodiesel has the potential to substitute fossil fuels as an alternative source of energy. Although biodiesel has many benefits to offer, manufacturing biodiesel on an industrial scale is uneconomical as a high cost of feedstock is required. A novel sulfonated and magnetic catalyst synthesised from a palm kernel shell (PMB-SO3H) was first introduced in this study for methyl ester or biodiesel production to reduce capital costs. The wasted palm kernel shell (PKS) biochar impregnated with ferrite Fe3O4 was synthesised with concentrated sulphuric acid through the sulfonation process. The SEM, EDX, FTIR, VSM and TGA characterization of the catalysts were presented. Then, the optimisation of biodiesel synthesis was catalysed by PMB-SO3H via the Response Surface Methodology (RSM). It was found that the maximum biodiesel yield of 90.2% was achieved under these optimum operating conditions: 65 °C, 102 min, methanol to oil ratio of 13:1 and the catalyst loading of 3.66 wt%. Overall, PMB-SO3H demonstrated acceptable catalysing capability on its first cycle, which subsequently showed a reduction of the reusability performance after 4 cycles. An important practical implication is that PMB-SO3H can be established as a promising heterogeneous catalyst by incorporating an iron layer which can substantially improve the catalyst separation performance in biodiesel production.
Biodiesels and biolubricants are synthetic esters produced mainly via a transesterification of other esters from bio-based resources, such as plant-based oils or animal fats. Microwave heating has been used to enhance transesterification reaction by converting an electrical energy into a radiation, becoming part of the internal energy acquired by reactant molecules. This method leads to major energy savings and reduces the reaction time by at least 60% compared to a conventional heating via conduction and convection. However, the application of microwave heating technology alone still suffers from non-homogeneous electromagnetic field distribution, thermally unstable rising temperatures, and insufficient depth of microwave penetration, which reduces the mass transfer efficiency. The strategy of integrating multiple technologies for biodiesel and biolubricant production has gained a great deal of interest in applied chemistry. This review presents an advanced transesterification process that combines microwave heating with other technologies, namely an acoustic cavitation, a vacuum, ionic solvent, and a supercritical/subcritical approach to solve the limitations of the stand-alone microwave-assisted transesterification. The combined technologies allow for the improvement in the overall product yield and energy efficiency. This review provides insights into the broader prospects of microwave heating in the production of bio-based products.
The present study defines a novel green method for the synthesis of the nickel oxide nanocatalyst by using an aqueous latex extract of the Ficus elastic. The catalyst was examined for the conversion of novel Brachychiton populneus seed oil (BPSO) into biodiesel. The Brachychiton populneus seeds have a higher oil content (41 wt%) and free fatty acid value (3.8 mg KOH/g). The synthesised green nanocatalyst was examined by the Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-Ray (EDX) spectroscopy, X-Ray diffraction (XRD) spectroscopy and scanning electron microscopy (SEM). The obtained results show that the synthesised green nanocatalyst was 22-26 nm in diameter and spherical-cubic in shape with a higher rate of catalytic efficiency. It was utilised further for the conversion of BPSO into biofuel. Due to the high free fatty acid value, the biodiesel was synthesised by the two-step process, i.e., pretreatment of the BPSO by means of acid esterification and then followed by the transesterification reaction. The acidic catalyst (H2SO4) was used for the pretreatment of BPSO. The optimum condition for the transesterification of the pretreated BPSO was 1:9 of oil-methanol molar ratio, 2.5 wt % of prepared nanocatalyst concentration and 85 °C of reaction temperature corresponding to the highest biodiesel yield of 97.5 wt%. The synthesised biodiesel was analysed by the FT-IR and GC-MS technique to determine the chemical composition of fatty acid methyl esters. Fuel properties of Brachychiton populneus seed oil biodiesel (BPSOB) were also examined, compared, and it falls in the prescribed range of ASTM standards.
The purpose of this paper was to carry out microwave induced pyrolysis of oil palm biomass (shell and fibers) with the help of char as microwave absorber (MA). Rapid heating and yield of microwave pyrolysis products such as bio-oil, char, and gas was found to depend on the ratio of biomass to microwave absorber. Temperature profiles revealed the heating characteristics of the biomass materials which can rapidly heat-up to high temperature within seconds in presence of MA. Some characterization of pyrolysis products was also presented. The advantage of this technique includes substantial reduction in consumption of energy, time and cost in order to produce bio-oil from biomass materials. Large biomass particle size can be used directly in microwave heating, thus saving grinding as well as moisture removal cost. A synergistic effect was found in using MA with oil palm biomass.
Basal stem rot disease caused by the basidiomycete fungus, Ganoderma boninense is the most serious disease of oil palm in Malaysia. The disease can be identified by dry rotting of internal parts of the stem with fruiting bodies or basidiomata of the fungus occurring at the oil palm stem base. The stem lesion allows the basal stem rot disease to be distinguished from the other root diseases
Effects of breading materials and deep-fat frying on fat uptake, moisture content and fatty acid composition of the black pomfret (Parastromateus niger) fillets. Black pomfret fillets both breaded and non-breaded were deep-fat fried in sunflower oil and palm olein. Fat uptake, moisture content and fatty acid composition in the fillets were determined. Total fat content in the fillets of both breaded and un-breaded fillets increased significantly (p
Pretreatment is an essential upstream process to deconstruct oil palm empty fruit bunch fiber (OPEFBF) prior to sugars production. This study aimed to investigate the efficiency of OPEFBF pretreatment using palm oil mill effluent (POME) as solvent. The effect of alkali catalyst (5%w/w NaOH and ammonia), temperature (90,120,135 °C) and time (60,120,180 min) on the efficiency of pretreatment (OPEFBF-to-solvent ratio of 1:25) was also investigated. The results indicated that POME-pretreatment (135 °C, 180 min) enhanced glucose yield by only ~56%. Glucose production was increased about 5.8-fold to 495.3 ± 5.9 mg g-1 OPEFBF when NaOH was added in POME-pretreatment (Na-P). The xylose production from OPEFBF was increased about 3.7-fold after ammonia-catalyzed POME-pretreatment. About 12.1 ± 0.2 g L-1 of ethanol was produced from Na-P-hydrolysate at molar conversion of 59.4 ± 1.4%. This research provides new insight into the use of POME as a cost-effective pretreatment solvent of OPEFBF to reduce upstream process cost by cutting down water usage.
Biomass and lipid production by the marine diatom Chaetoceros affinis were characterized under continuous light with aeration. Media based on palm oil mill effluent (POME; 10, 20 and 30 % v/v in distilled water) were used together with a standard control medium. The maximum biomass concentration on day 12 of batch cultures in control medium was 821 ± 71 mg L-1. Under identical conditions, in the best POME medium (20 % POME v/v in distilled water with other inorganic components), the biomass concentration was reduced by ∼11 % to 734 ± 66 mg L-1. The lipid content of the biomass grown in the control medium was 50.8 ± 4.5 % by dry weight, but was a little lower (48.9 ± 4.1 % by dry wt) in the above specified best POME medium. In the best POME medium, oleic acid was the major fatty acid (72.3 ± 5.2 % by weight) in the total lipids extracted from the biomass and monounsaturated fatty acids were the main type of fatty acids (74.6 ± 5.2 %). POME levels of >20 % in the medium suppressed both biomass and lipid production relative to the medium with 20 % POME.
In this study we used a laser ablation technique for preparation of silver nanoparticles. The fabrication process was carried out by ablation of a silver plate immersed in palm oil. A pulsed Nd:YAG laser at a wavelength of 1064 nm was used for ablation of the plate at different times. The palm coconut oil allowed formation of nanoparticles with very small and uniform particle size, which are dispersed very homogeneously within the solution. The obtained particle sizes for 15 and 30 minute ablation times were 2.5 and 2 nm, respectively. Stability study shows that all of the samples remained stable for a reasonable period of time.
The melting curves of 11 vegetable oils have been characterised. Vegetable oil samples that were cooled at a constant rate (5 degrees C/min) from the melt showed between one and seven melting endotherms upon heating at four different heating rates (1, 5, 10 and 20 degrees C/min) in a differential scanning calorimeter (DSC). Triacylglycerol (TAG) profiles and iodine value analyses were used to complement the DSC data. Generally, the melting transition temperature shifted to higher values with increased rates of heating. The breadth of the melting endotherm and the area under the melting peak also increased with increasing heating rate. Although the number of endothermic peaks was dependent on heating rate, the melting curves of the oil samples were not straightforward in that there was no correlation between the number of endothermic peaks and heating rates. Multiple melting behaviour in DSC experiments with different heating rates could be explained by: (1) the melting of TAG populations with different melting points; and (2) TAG crystal reorganisation effects. On the basis of the corollary results obtained, vegetable oils and fats may be distinguished from their offset-temperature (Toff) values in the DSC melting curves. The results showed that Toff values of all oil samples were significantly (p < 0.01) different in the melting curves scanned at four different scanning rates. These calorimetric results indicate that DSC is a valuable technique for studying vegetable oils.
Palm oil processing is a multi-stage operation which generates large amount of effluent. On average, palm oil mill effluent (POME) may contain up to 51, 000 mg/L COD, 25,000 mg/L BOD, 40,000 TS and 6000 mg/L oil and grease. Due to its potential to cause environmental pollution, palm oil mills are required to treat the effluent prior to discharge. Biological treatments using open ponding system are widely used for POME treatment. Although these processes are capable of reducing the pollutant concentrations, they require long hydraulic retention time and large space, with the effluent frequently failing to satisfy the discharge regulation. Due to more stringent environmental regulations, research interest has recently shifted to the development of polishing technologies for the biologically-treated POME. Various technologies such as advanced oxidation processes, membrane technology, adsorption and coagulation have been investigated. Among these, advanced oxidation processes have shown potentials as polishing technologies for POME. This paper offers an overview on the POME polishing technologies, with particularly emphasis on advanced oxidation processes and their prospects for large scale applications. Although there are some challenges in large scale applications of these technologies, this review offers some perspectives that could help in overcoming these challenges.