Food manufacturers are interested in developing emulsion-based products into nutritional foods by using beneficial oils, such as fish oil and virgin coconut oil (VCO). In this study, the physicochemical properties of a VCO oil-in-water emulsion was investigated and compared to other commercial oil-in-water emulsion products (C1, C2, C3, and C4). C3 exhibited the smallest droplet size of 3.25 µm. The pH for the emulsion samples ranged from 2.52 to 4.38 and thus were categorised as acidic. In a texture analysis, C2 was described as the most firm, very adhesive and cohesive, as well as having high compressibility properties. From a rheological viewpoint, all the emulsion samples exhibited non-Newtonian behaviour, which manifested as a shear-thinning property. The G'G'' crossover illustrated by the VCO emulsion in the amplitude sweep graph but not the other commercial samples illustrated that the VCO emulsion had a better mouthfeel. In this context, the VCO emulsion yielded the highest zeta potential (64.86 mV), which was attributed to its strong repulsive forces, leading to a good dispersion system. C2 comprised the highest percentage of fat among all emulsion samples, followed by the VCO emulsion, with 18.44% and 6.59%, respectively.
Agro-waste from the bark of Metroxylon sagu (sago) was studied as a low cost and effective oil sorbent in dry and aqueous environments. Sorption study was conducted using untreated sago bark (SB) and esterified sago bark (ESB) in used engine oil. Characterization study showed that esterification has successfully improved the hydrophobicity, buoyancy, surface roughness and oil sorption capacity of ESB. Sorption study revealed that water uptake of SB is higher (30 min static: 2.46 g/g, dynamic: 2.67 g/g) compared with ESB (30 min static: 0.18 g/g, dynamic: 0.14 g/g). ESB, however, showed higher oil sorption capacity in aqueous environment (30 min static: 2.30 g/g, dynamic: 2.14) compared with SB (30 min static: 0 g/g, dynamic: 0 g/g). ESB has shown great poTENTial as effective oil sorbent in aqueous environment due to its high oil sorption capacity, low water uptake and high buoyancy.
Anode biofilm is a crucial component in microbial fuel cells (MFCs) for electrogenesis. Better knowledge about the biofilm development process on electrode surface is believed to improve MFC performance. In this study, double-chamber microbial fuel cell was operated with diluted POME (initial COD = 1,000 mg L(-1)) and polyacrylonitrile carbon felt was used as electrode. The maximum power density, COD removal efficiency and Coulombic efficiency were found as 22 mW m(-2), 70 and 24 %, respectively. FTIR and TGA analysis confirmed the formation of biofilm on the electrode surface during MFC operation. The impact of anode biofilm on anodic polarization resistance was investigated using electrochemical impedance spectroscopy (EIS) and microbial community changes during MFC operation using denaturing gradient gel electrophoresis (DGGE). The EIS-simulated results showed the reduction of charge transfer resistance (R ct) by 16.9 % after 14 days of operation of the cell, which confirms that the development of the microbial biofilm on the anode decreases the R ct and therefore improves power generation. DGGE analysis showed the variation in the biofilm composition during the biofilm growth until it forms an initial stable microbial community, thereafter the change in the diversity would be less. The power density showed was directly dependent on the biofilm development and increased significantly during the initial biofilm development period. Furthermore, DGGE patterns obtained from 7th and 14th day suggest the presence of less diversity and probable functional redundancy within the anodic communities possibly responsible for the stable MFC performance in changing environmental conditions.
Plasticized poly(lactic acid) PLA with epoxidized vegetable oils (EVO) were prepared using a melt blending method to improve the ductility of PLA. The plasticization of the PLA with EVO lowers the Tg as well as cold-crystallization temperature. The tensile properties demonstrated that the addition of EVO to PLA led to an increase of elongation at break, but a decrease of tensile modulus. Plasticized PLA showed improvement in the elongation at break by 2058% and 4060% with the addition of 5 wt % epoxidized palm oil (EPO) and mixture of epoxidized palm oil and soybean oil (EPSO), respectively. An increase in the tensile strength was also observed in the plasticized PLA with 1 wt % EPO and EPSO. The use of EVO increases the mobility of the polymeric chains, thereby improving the flexibility and plastic deformation of PLA. The SEM micrograph of the plasticized PLA showed good compatible morphologies without voids resulting from good interfacial adhesion between PLA and EVO. Based on the results of this study, EVO may be used as an environmentally friendly plasticizer that can improve the overall properties of PLA.
A sequencing batch reactor (SBR) with a working volume of 8 L and an exchange ratio of 25% was used to enrich biomass for the treatment of the anaerobically treated low pH palm oil mill effluent (POME). The influent concentration was stepwise increased from 5000 ± 500 mg COD/L to 11,500 ± 500 mg COD/L. The performance of the reactor was monitored at different organic loading rates (OLRs). It was found that approximately 90% of the COD content of the POME wastewater was successfully removed regardless of the OLR applied to the SBR. Cycle studies of the SBR show that the oxygen uptake by the biomass while there is no COD reduction may be due to the oxidation of the storage product by the biomass. Further, the growth kinetic parameters of the biomass were determined in batch experiments using respirometer. The maximum specific growth rate (μmax) was estimated to be 1.143 day(-1) while the half saturation constant (Ks) with respect to COD was determined to be 0.429 g COD/L. The decay coefficient (bD) and biomass yield (Y) were found to be 0.131 day(-1) and 0.272 mg biomass/mg COD consumed, respectively.
The binary effect of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) on heat of hydration of aerated concrete was studied. Three aerated concrete mixes were prepared, namely, concrete containing 100% ordinary Portland cement (control sample or Type I), binary concrete made from 50% POFA (Type II), and ternary concrete containing 30% POFA and 20% PFA (Type III). It is found that the temperature increases due to heat of hydration through all the concrete specimens especially in the control sample. However, the total temperature rises caused by the heat of hydration through both of the new binary and ternary concrete were significantly lower than the control sample. The obtained results reveal that the replacement of Portland cement with binary and ternary materials is beneficial, particularly for mass concrete where thermal cracking due to extreme heat rise is of great concern.
The aim of this study was to optimize the antioxidant activity of Piper nigrum L. essential oil extracted using the supercritical carbon dioxide (SC-CO₂) technique. Response surface methodology was applied using a three-factor central composite design to evaluate the effects of three independent extraction variables: pressure of 15-30 MPa, temperature of 40-50 °C and dynamic extraction time of 40-80 min. The DPPH radical scavenging method was used to evaluate the antioxidant activity of the extracts. The results showed that the best antioxidant activity was achieved at 30 MPa, 40 °C and 40 min. The extracts were analyzed by GC-FID and GC-MS. The main components extracted using SC-CO₂ extraction in optimum conditions were β-caryophyllene (25.38 ± 0.62%), limonene (15.64 ± 0.15%), sabinene (13.63 ± 0.21%), 3-carene (9.34 ± 0.04%), β-pinene (7.27 ± 0.05%), and α-pinene (4.25 ± 0.06%). The essential oil obtained through this technique was compared with the essential oil obtained using hydro-distillation. For the essential oil obtained by hydro-distillation, the most abundant compounds were β-caryophyllene (18.64 ± 0.84%), limonene (14.95 ± 0.13%), sabinene (13.19 ± 0.17%), 3-carene (8.56 ± 0.11%), β-pinene (9.71 ± 0.12%), and α-pinene (7.96 ± 0.14%). Radical scavenging activity of the extracts obtained by SC-CO₂ and hydro-distillation showed an EC₅₀ of 103.28 and 316.27 µg mL(-1) respectively.
In the present study, polyembryoids of oil palm (Elaeis guineensis Jacq.) were cryopreserved with successful revival of 68 % for the first time using the droplet vitrification technique. Excised polyembryoids (3-5-mm diameter) from 3-month-old in vitro cultures were pre-cultured for 12 h in liquid Murashige and Skoog medium supplemented with 0.5 M sucrose. The polyembryoids were osmoprotected in loading solution [10% (w/v) dimethyl sulphoxide (DMSO) plus 0.7 M sucrose] for 30 min at room temperature and then placed on aluminium strips where they were individually drenched in chilled droplets of vitrification solution (PVS2) [30% (w/v) glycerol plus 15% (w/v) ethylene glycol (EG) plus 15% (w/v) DMSO plus 0.4 M sucrose] for 10 min. The aluminium strips were enclosed in cryovials which were then plunged quickly into liquid nitrogen and kept there for 1 h. The polyembryoids were then thawed and unloaded (using 1.2 M sucrose solution) with subsequent transfer to regeneration medium and stored in zero irradiance. Following for 10 days of storage, polyembryoids were cultured under 16 h photoperiod of 50 μmol m(-2) s(-1) photosynthetic photon flux density, at 23 ± 1 °C. Post-thaw growth recovery of 68% was recorded within 2 weeks of culture, and new shoot development was observed at 4 weeks of growth. Scanning electron microscopy revealed that successful regeneration of cryopreserved polyembryoids was related to maintenance of cellular integrity, presumably through PVS2 exposure for 10 min. The present study demonstrated that cryopreservation by droplet vitrification enhanced the regeneration percentages of oil palm in comparison with the conventional vitrification method previously reported.
Palm oil mill effluent (POME) is a highly contaminating wastewater due to its high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Conventional treatment methods require longer residence time (10-15 days) and higher operating cost. Owing to this, finding a suitable and efficient method for the treatment of POME is crucial. In this investigation, ultrasound cavitation technology has been used as an alternative technique to treat POME. Cavitation is the phenomenon of formation, growth and collapse of bubbles in a liquid. The end process of collapse leads to intense conditions of temperature and pressure and shock waves which assist various physical and chemical transformations. Two different ultrasound systems i.e. ultrasonic bath (37 kHz) and a hexagonal triple frequency ultrasonic reactor (28, 40 and 70 kHz) of 15 L have been used. The results showed a fluctuating COD pattern (in between 45,000 and 60,000 mg/L) while using ultrasound bath alone, whereas a non-fluctuating COD pattern with a final COD of 27,000 mg/L was achieved when hydrogen peroxide was introduced. Similarly for the triple frequency ultrasound reactor, coupling all the three frequencies resulted into a final COD of 41,300 mg/L compared to any other individual or combination of two frequencies. With the possibility of larger and continuous ultrasonic cavitational reactors, it is believed that this could be a promising and a fruitful green process engineering technique for the treatment of POME.
The culture conditions for gibberellic acid (GA3) production by the fungus Penicillium variable (P. variable) was optimized using a statistical tool, response surface methodology (RSM). Interactions of culture conditions and optimization of the system were studied using Box-Behnken design (BBD) with three levels of three variables in a batch flask reactor. Experimentation showed that the model developed based on RSM and BBD had predicted GA3 production with R(2) = 0.987. The predicted GA3 production was optimum (31.57 mg GA3/kg substrate) when the culture conditions were at 7 days of incubation period, 21% v/w of inoculum size, and 2% v/w of olive oil concentration as a natural precursor. The results indicated that RSM and BBD methods were effective for optimizing the culture conditions of GA3 production by P. variable mycelia.
Solubility and matrix play an important role in the gut lumen in delivering bioactive compounds to the absorptive surface of enterocytes. The purpose of this study was to determine the effect of certain commonly consumed lipids, soybean, olive and corn oil, on the transport and conjugation of flavonols (myricetin, quercetin, kaempferol and galangin) using the conjugation-competent co-cultured Caco-2/HT29-MTX intestinal cell monolayer model. To enable identification and quantification of conjugates, each flavonol was enzymatically glucuronidated or sulphated, then analysed by HPLC with triple quadrupole mass spectrometric detection. Quantification showed large differences in mass spectrometric peak area response factors between the aglycones and many of the conjugates, with galangin-sulphate for example ionising ∼15-fold better than galangin. Flavonol aglycones and conjugates were transported to the basolateral side of Caco-2/HT29-MTX co-cultures. The total amount of methyl, sulphate and glucuronide conjugates was in the order: galangin > quercetin > kaempferol > myricetin. All oils inhibited the transport and conjugation of galangin, the most hydrophobic flavonol, whereas they increased the sulphation, and to some extent glucuronidation, of quercetin and kaempferol. The results show that the lipid matrix has the potential to modify both transport and conjugation of dietary flavonols, but that the effect depends upon the structure and hydrophobicity.
For the first time 5-hydroxymethyl-2-furaldehyde (HMF) was separated from crude palm oil (CPO), and its authenticity was determined using an RP-HPLC method. Separation was accomplished with isocratic elution of a mobile phase comprising water and methanol (92:8 v/v) on a Purospher Star RP-18e column (250mm×4.6mm, 5.0μm). The flow rate was adjusted to 1ml/min and detection was performed at 284nm. The method was validated, and results obtained exhibit a good recovery (95.58% to 98.39%). Assessment of precision showed that the relative standard deviations (RSD%) of retention times and peak areas of spiked samples were less than 0.59% and 2.66%, respectively. Further, the limit of detection (LOD) and LOQ were 0.02, 0.05mg/kg, respectively, and the response was linear across the applied ranges. The crude palm oil samples analysed exhibited HMF content less than 2.27mg/kg.
As Malaysia is one of the world's largest producer of palm oil, large amounts of palm oil mill effluent (POME) is generated. It was found that negatively charged components are accountable for POME color. An attempt was made to remove residual contaminants after conventional treatment using anion base resin. Adsorption experiments were carried out in fixed bed column. Various models such as the Thomas, the Yoon-Nelson, the Wolborska and BDST model were used to fit the experimental data. It was found that only the BDST model was fitted well at the initial breakthrough time. A wavelet neural network model (WNN) was developed to model the breakthrough curves in fixed bed column for multicomponent system. The results showed that the WNN model described breakthrough curves better than the commonly used models. The effects of pH, flow rate and bed depth on column performance were investigated. It was found that the highest uptake capacity was obtained at pH 3. The exhaustion time appeared to increase with increase in bed length and decrease in flow rate.
The composting of lignocellulosic oil palm empty fruit bunch (OPEFB) with continuous addition of palm oil mill (POME) anaerobic sludge which contained nutrients and indigenous microbes was studied. In comparison to the conventional OPEFB composting which took 60-90 days, the rapid composting in this study can be completed in 40 days with final C/N ratio of 12.4 and nitrogen (2.5%), phosphorus (1.4%), and potassium (2.8%), respectively. Twenty-seven cellulolytic bacterial strains of which 23 strains were closely related to Bacillus subtilis, Bacillus firmus, Thermobifida fusca, Thermomonospora spp., Cellulomonas sp., Ureibacillus thermosphaericus, Paenibacillus barengoltzii, Paenibacillus campinasensis, Geobacillus thermodenitrificans, Pseudoxanthomonas byssovorax which were known as lignocellulose degrading bacteria and commonly involved in lignocellulose degradation. Four isolated strains related to Exiguobacterium acetylicum and Rhizobium sp., with cellulolytic and hemicellulolytic activities. The rapid composting period achieved in this study can thus be attributed to the naturally occurring cellulolytic and hemicellulolytic strains identified.
Palm oil esters (POEs) are esters derived from palm oil and oleyl alcohol have great potential in the cosmetic and pharmaceutical industries due to the excellent wetting behavior of the esters without the oily feel. The role of oil-in-water nanoemulsions loaded with tocotrienol sedimentation behavior was studied. LUMiFuge® 116 particle separation analyzer was used to investigate the sedimentation behavior of POEs/tocotrienol/xanthan gum nanoemulsion system during centrifugation. Analyzing the sedimentation kinetics of dispersions in a centrifugal field also yields information about the rheological behavior and structural stability.
Poly(ethyl hydrazide)-grafted oil palm empty fruit bunch fibre (peh-g-opefb) was successfully prepared by heating poly(methyl acrylate)-grafted opefb (pma-g-opefb) at 60 °C for 4 h with a solution of hydrazine hydrate (15% v/v) in ethanol. The Fourier transform infrared spectrum of the product shows a secondary amine peak at 3267 cm⁻¹, with amide carbonyl peaks at 1729 cm⁻¹ and 1643 cm⁻¹. The chelating ability of peh-g-opefb was tested with copper ion in aqueous solution. A batch adsorption study revealed that maximum adsorption of copper ion was achieved at pH 5. An isotherm study showed the adsorption follows a Langmuir model, with a maximum adsorption capacity of 43.48 mg g-1 at 25 °C. A kinetic study showed that the adsorption of copper ion rapidly reaches equilibrium and follows a pseudo-second-order kinetic model, with a constant rate of 7.02 × 10⁻⁴ g mg⁻¹ min⁻¹ at 25 °C. The Gibbs free energy, ∆G⁰, value is negative, indicating a spontaneous sorption process. Entropy, ∆S⁰, gives a positive value, indicating that the system is becoming increasingly disordered after the adsorption of copper ion. A positive enthalpy value, ∆H⁰, shows that the endothermic process takes place during the adsorption and is more favourable at high temperatures.
The chemical compositions of the essential oil of the rhizome, leaf and stem of Hornstedtia leonurus Retz., collected from Negeri Sembilan, Malaysia,are reported for the first time. The essential oils were extracted using hydrodistillation and analyzed by gas chromatography (GC-FID) and gas chromatography/mass spectrometry (GC/MS). Seventeen (96.4%), thirteen (89.2%) and nine components (98.8%) were successfully identified from the rhizome, stem and leaf oils, respectively. Phenylpropanoids were found to be the major fraction, with methyleugenol being the most abundant compound in all oils with percentage compositions of 76.4% (rhizome), 80.3% (stem) and 74.5% (leaf).
Anaerobic digestion for palm oil mill effluent (POME) is widely known for its potential in biogass production. In this study, the potential of using cattle manure for biogas production in complete mix anaerobic bioreactor was investigated using POME at unregulated pH and temperature. Two identical bioreactors were used in this study; namely R1 and R2 fed with cattle manure without and with POME as inoculum, respectively. Both bioreactors were allowed for five days to run in batch mode followed by semi continuous operations at HRT of 20 days. R2 produced 41% methane content compared to 18% produced in R1. A better COD percentage reduction of 45% was found in R2 which was operated with POME as inoculum compared to R1 with 35%. These results indicated that POME as inoculum has an influence on the start-up time and the rate of biogas produced.This findings will help in waste reduction.
The formation of 3-monochloropropane-1,2-diol (3-MCPD) esters in refined palm oil during deodorisation is attributed to the intrinsic composition of crude palm oil. Utilising D-optimal design, the effects of the degumming and bleaching processes on the reduction in 3-MCPD ester formation in refined palm oil from poor-quality crude palm oil were studied relative to the palm oil minor components that are likely to be their precursors. Water degumming remarkably reduced 3-MCPD ester formation by up to 84%, from 9.79 mg/kg to 1.55 mg/kg. Bleaching with synthetic magnesium silicate caused a further 10% reduction, to 0.487 mg/kg. The reduction in 3-MCPD ester formation could be due to the removal of related precursors prior to the deodorisation step. The phosphorus content of bleached palm oil showed a significant correlation with 3-MCPD ester formation.
The ageing of the bitumen during storage, mixing, transport and laying on the road, as well as in service life, are the most important problems presented by the use of bitumen in pavements. This paper investigates the possibility of using waste cooking oil (WCO), which is a waste material that pollutes landfills and rivers, as an alternative natural rejuvenating agent for aged bitumen to a condition that resembles the original bitumen. With this target, the physical and chemical properties of the original bitumen, aged bitumen and rejuvenated bitumen were measured and compared by the bitumen binder tests - softening point, penetration, Brookfield viscosity, dynamic shear rheometer and Fourier transform infrared spectroscopy. In addition, the behaviour of the WCO rejuvenated bitumen is investigated and compared with virgin bitumen after using the rolling thin film oven ageing process. In general, the results showed that using 3-4% of WCO the aged bitumen group 40/50 was rejuvenated to a condition that closely resembled the physical, rheological properties of the original bitumen (80/100), however, there was a difference in the tendency to ageing between the WCO rejuvenated bitumen and the virgin bitumen during mixing, transport and laying on the road.