This study explores an eco-friendly delignification technique for raw oil palm leaves (OPL), highlighting the optimized conditions of choline chloride-lactic acid deep eutectic solvent (DES)-mediated ball milling pretreatment to maximize the co-production yields of highly crystalline cellulose and lignin. Our five-level-four-factor Taguchi design identified the optimal reaction settings for cellulose production (85.83 % yield, 47.28 % crystallinity) as 90-minute milling, 1500 rpm, mill-ball size ratio of 30:10, ball-to-sample mass ratio of 20:1, DES-to-sample mass ratio of 3:1. Conversely, the maximal lignin extraction yield (35.23 %) occurred optimally at 120-minute milling, 600 rpm, mill-ball size ratio of 25:5, ball-to-sample mass ratio of 20:1 and DES-to-sample mass ratio of 9:1. Statistical results showed that milling frequency (p-value ≤ 0.0001) was highly significant in improving cellulose crystallinity and yield, while DES-to-sample mass ratio (p-value ≤ 0.0001) was the most impacting on lignin yield. The thermogravimetric method affirmed the elevated cellulose thermal stability, corroborating the enhanced cellulose content (40.14 % to 73.67 %) alongside elevated crystallinity and crystallite size (3.31 to 4.72 nm) shown by X-ray diffractograms. The increased surface roughness seen in micrographs mirrored the above-said post-treatment changes. In short, our optimized one-pot dual-action pretreatment effectively delignified the raw OPL to produce cellulose-rich material with enhanced crystallinity and lignin solidity.
Nanocrystalline cellulose (NCC) was isolated from oil palm empty fruit bunch pulp (EFBP) using ultrasound assisted acid hydrolysis. The obtained NCC was analysed using FESEM, XRD, FTIR, and TGA, and compared with raw empty fruit bunch fibre (REFB), empty fruit bunch pulp (EFBP), and treated empty fruit bunch pulp (TEFBP). Based on FESEM analysis, it was found that NCC has a spherical shaped after acid hydrolysis with the assistance of ultrasound. This situation was different compared to previous studies that obtained rod-like shaped of NCC. Furthermore, the crystallinity of NCC is higher compared to REFB and EFBP. According to thermal stability, the NCC obtained shows remarkable sign of high thermal stability compared to REFB and EFBP.
An appropriate technology for waste utilisation, especially for a large amount of abundant pressed-shredded oil palm empty fruit bunch (OFEFB), is important for the oil palm industry. Self-sustained pyrolysis, whereby oil palm biomass was combusted by itself to provide the heat for pyrolysis without an electrical heater, is more preferable owing to its simplicity, ease of operation and low energy requirement. In this study, biochar production under self-sustained pyrolysis of oil palm biomass in the form of oil palm empty fruit bunch was tested in a 3-t large-scale pool-type reactor. During the pyrolysis process, the biomass was loaded layer by layer when the smoke appeared on the top, to minimise the entrance of oxygen. This method had significantly increased the yield of biochar. In our previous report, we have tested on a 30-kg pilot-scale capacity under self-sustained pyrolysis and found that the higher heating value (HHV) obtained was 22.6-24.7 MJ kg(-1) with a 23.5%-25.0% yield. In this scaled-up study, a 3-t large-scale procedure produced HHV of 22.0-24.3 MJ kg(-1) with a 30%-34% yield based on a wet-weight basis. The maximum self-sustained pyrolysis temperature for the large-scale procedure can reach between 600 °C and 700 °C. We concluded that large-scale biochar production under self-sustained pyrolysis was successfully conducted owing to the comparable biochar produced, compared with medium-scale and other studies with an electrical heating element, making it an appropriate technology for waste utilisation, particularly for the oil palm industry.
Resistant starch type III (RS3 ) was produced from sago (Metroxylon sagu) and evaluated for its characteristics as a prebiotic. Two RS3 samples designated sago RS and HCl-sago RS contained 35.71% and 68.30% RS, respectively, were subjected to hydrolyses by gastric juice and digestive enzymes and to absorption. Both sago RS and HCl-sago RS were resistant to 180 min hydrolysis by gastric acidity at pH 1 to 4 with less than 0.85% hydrolyzed. Both samples were also resistant toward hydrolysis by gastrointestinal tract enzymes and intestinal absorption with 96.75% and 98.69% of RS3 were recovered respectively after 3.5 h digestion and overnight dialysis at 37 °C. Sago RS3 supported the growth of both beneficial (lactobacilli and Bifidobacteria) and pathogenic microbes (Escherichia coli, Campylobacter coli, and Clostridium perfringens) in the range of 2.60 to 3.91 log10 CFU/mL. Hence, prebiotic activity score was applied to describe the extent to which sago RS3 supports selective growth of the lactobacilli and bifidobacteria strains over pathogenic bacteria. The highest scores were obtained from Bifidobacterium sp. FTDC8943 grown on sago RS (+0.26) and HCl-sago RS (+0.24) followed by L. bulgaricus FTDC1511 grown on sago RS (+0.21). The findings had suggested that sago RS3 has the prebiotic partial characteristics and it is suggested to further assess the suitability of sago RS3 as a prebiotic material.
Oil spill constitutes a major source of fresh and seawater pollution as a result of accidental discharge from tankers, marine engines, and underwater pipes. Therefore, the need for cost-effective and environmental friendly sorbent materials for oil spill cleanup cannot be overemphasized. The present work focuses on the preliminary study of empty palm fruit bunch fibre as a promising sorbent material. The morphology of the unmodified empty palm fruit bunch, EPFB fibre, was examined using an optical microcopy, scanning electron microcopy coupled with EDX and X-ray diffraction. The effects of oil volume, fibre weight, and time on oil absorption of EPFB fibre were evaluated with new engine oil from the model oil. The results show that EPFB fibre consists of numerous micro pores, hydrophobic, and partially crystalline and amorphous with approximately 13.5% carbon. The oil absorbency of the fibre increased with the increase in oil volume, immersion time, and fibre weight. However, sorption capacity decreased beyond 3 g in 100 mL. Additionally unmodified EPFB fibre showed optimum oil sorption efficiency of approximately 2.8 g/g within three days of immersion time.
In this study, oil palm mesocarp fiber (OPMF) was treated with superheated steam (SHS) in order to modify its characteristics for biocomposite applications. Treatment was conducted at temperatures 190-230 °C for 1, 2 and 3 h. SHS-treated OPMF was evaluated for its chemical composition, thermal stability, morphology and crystallinity. OPMF treated at 230 °C exhibited lower hemicellulose content (9%) compared to the untreated OPMF (33%). Improved thermal stability of OPMF was found after the SHS treatment. Moreover, SEM and ICP analyses of SHS-treated OPMF showed that silica bodies were removed from OPMF after the SHS treatment. XRD results exhibited that OPMF crystallinity increased after SHS treatment, indicating tougher fiber properties. Hemicellulose removal makes the fiber surface more hydrophobic, whereby silica removal increases the surface roughness of the fiber. Overall, the results obtained herewith suggested that SHS is an effective treatment method for surface modification and subsequently improving the characteristics of the natural fiber. Most importantly, the use of novel, eco-friendly SHS may contribute to the green and sustainable treatment for surface modification of natural fiber.
A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate) (PBAT), which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB) fiber was successfully done by grafting succinic anhydride (SAH) onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG) after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP) initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24%) compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA)/differential thermogravimetric (DTG) thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites' thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens.
Poly(3-hydroxybutyrate-co-38 mol%-3-hydroxyvalerate) [P(3HB-co-38mol%-3HV)] was produced by Cupriavidus sp. USMAA2-4 in the presence of oleic acid and 1-pentanol. Due to enormous production of empty fruit bunch (EFB) in the oil palm plantation and high production cost of P(3HB-co-3HV), oil palm EFB fibers were used for biocomposites preparation. In this study, maleic anhydride (MA) and benzoyl peroxide (DBPO) were used to improve the miscibility between P(3HB-co-3HV) and EFB fibers. Introduction of MA into P(3HB-co-3HV) backbone reduced the molecular weight and improved the thermal stability of P(3HB-co-3HV). Thermal stability of P(3HB-co-3HV)/EFB composites was shown to be comparable to that of commercial packaging product. Composites with 35% EFB fibers content have the highest tensile strength compared to 30% and 40%. P(3HB-co-3HV)/EFB blends showed less chemicals leached compared to commercial packaging.
A mathematical model describing chemical kinetics of transesterification of palm-based methyl esters with trimethylolpropane has been developed. The model was developed by utilizing nonlinear regression method, which is an efficient and powerful way to determine rate constants for both forward and reverse reactions. A comparison with previous study which excludes the reverse reactions was made. The model was based on the reverse mechanism of transesterification reactions and describes concentration changes of trimethylolpropane, monoesters and diesters production. The developed model was validated against data from the literature. The reaction rate constants were determined using MATLAB version 7.2 and the ratios of rate constants obtained were well in agreement with those reported in the literature. A good correlation between model simulations and experimental data was observed. It was proven that both methods were able to predict the rate constants with plausible accuracy.
Oil palm fibre was used to prepare activated carbon using physiochemical activation method which consisted of potassium hydroxide (KOH) treatment and carbon dioxide (CO(2)) gasification. The effects of three preparation variables: the activation temperature, activation time and chemical impregnation (KOH:char) ratio on methylene blue (MB) uptake from aqueous solutions and activated carbon yield were investigated. Based on the central composite design (CCD), a quadratic model and a two factor interaction (2FI) model were respectively developed to correlate the preparation variables to the MB uptake and carbon yield. From the analysis of variance (ANOVA), the significant factors on each experimental design response were identified. The optimum activated carbon prepared from oil palm fibre was obtained by using activation temperature of 862 degrees C, activation time of 1h and chemical impregnation ratio of 3.1. The optimum activated carbon showed MB uptake of 203.83 mg/g and activated carbon yield of 16.50%. The equilibrium data for adsorption of MB on the optimum activated carbon were well represented by the Langmuir isotherm, giving maximum monolayer adsorption capacity as high as 400mg/g at 30 degrees C.
Palm shell was used to prepare activated carbon using potassium carbonate (K2CO3) as activating agent. The influence of carbonization temperatures (600-1000 degrees C) and impregnation ratios (0.5-2.0) of the prepared activated carbon on the pore development and yield were investigated. Results showed that in all cases, increasing the carbonization temperature and impregnation ratio, the yield decreased, while the adsorption of CO2 increased, progressively. Specific surface area of activated carbon was maximum about 1170 m2/g at 800 degrees C with activation duration of 2 h and at an impregnation ratio of 1.0.
The production of reducing sugars from sago waste via sequential ionic liquid dissolution-solid acid saccharification was optimized in this study. Ionic liquid dissolution of sago waste with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) was conducted prior to the solid acid saccharification with Amberlyst 15 (A15). The effect of time, temperature and substrate loading during dissolution reaction; and the effect of time, temperature and catalyst loading during saccharification reaction were examined by applying central composite design (CCD) separately. Both dissolution and saccharification reactions were respectively modeled into quadratic polynomial equations with good predictive accuracies. A high reducing sugars yield of 98.3% was obtained under the optimized conditions, i.e. dissolution at 1.75h, 160°C, 1.5% substrate loading, and saccharification at 0.5h, 130°C, 4% catalyst loading. From comparison studies of different saccharification schemes, the sequential ionic liquid dissolution-solid acid saccharification has proven to be a potential method in reducing sugars production from the lignocellulosic biomass.
The development and characterization of environmentally friendly bilayer films from sugar palm starch (SPS) and poly(lactic acid) (PLA) were conducted in this study. The SPS-PLA bilayer films and their individual components were characterized for their physical, mechanical, thermal and water barrier properties. Addition of 50% PLA layer onto 50% SPS layer (SPS50-PLA50) increased the tensile strength of neat SPS film from 7.74 to 13.65MPa but reduced their elongation at break from 46.66 to 15.53%. The incorporation of PLA layer significantly reduced the water vapor permeability as well as the water uptake and solubility of bilayer films which was attributed to the hydrophobic characteristic of the PLA layer. Furthermore, scanning electron microscopy (SEM) image of SPS50-PLA50 revealed lack of strong interfacial adhesion between the SPS and PLA. Overall, the incorporation of PLA layer onto SPS films enhances the suitability of SPS based films for food packaging.
Microcrystalline cellulose (MCC) extracted from empty fruit bunches (EFB), stalk and spikelet were characterised through physicochemical and microstructure analyses. Raw stalk fibres yielded the highest cellulose content (42.43%), followed by EFB (32.33%) and spikelet (18.83%). Likewise, lowest lignin and residual oil content was reported in raw stalk fibres compared to EFB and spikelet. SEM revealed significant changes on fibres' surface morphology throughout the extraction process. FTIR analysis showed that main characteristic peaks of hemicellulose and lignin was absent on the extracted MCC. The crystallinity index for MCC extracted from EFB (82.5%), stalk (82.2%) and spikelet (86.5%) was comparable to commercial MCC (81.9%). Results suggested stalk fibres is more preferable for the production of MCC compared to EFB and spikelet. Further rheological studies showed viscoelastic behaviour with no significant differences between commercial and stalk-based MCC, while modelling work showed ability to simulate complex deformation of the MCC-hydrogel/food mixture during processing/handling stage.
In this study, oil palm empty fruit bunch (OPEFBF) was pretreated with alkali, and lignin was extracted for further degradation into lower molecular weight phenolic compounds using enzymes and chemical means. Efficiency of monomeric aromatic compounds production from OPEFBF lignin via chemical (nitrobenzene versus oxygen) and enzymatic [cutinase versus manganese peroxidase (MnP)] approaches was investigated. The effects of sodium hydroxide concentration (2, 5, and 10% wt.) and reaction time (30, 90, and 180 minutes) on the yield of aromatic compounds were studied. The results obtained indicated that nitrobenzene oxidation produced the highest yield (333.17 ± 49.44 ppm hydroxybenzoic acid, 5.67 ± 0.25 ppm p-hydroxybenzaldehyde, 25.57 ± 1.64 ppm vanillic acid, 168.68 ± 23.23 ppm vanillin, 75.44 ± 6.71 ppm syringic acid, 815.26 ± 41.77 ppm syringaldehyde, 15.21 ± 2.19 ppm p-coumaric acid, and 44.75 ± 3.40 ppm ferulic acid), among the tested methods. High sodium hydroxide concentration (10% wt.) was needed to promote efficient nitrobenzene oxidation. However, less severe oxidation condition was preferred to preserve the hydroxycinnamic acids (p-coumaric acid and ferulic acid). Cutinase-catalyzed hydrolysis was found to be more efficient than MnP-catalyzed oxidation in the production of aromatic compounds. By hydrolyzed 8% wt. of lignin with 0.625 mL cutinase g(-1) lignin at pH 8 and 55°C for 24 hours, about 642.83 ± 14.45 ppm hydroxybenzoic acid, 70.19 ± 3.31 ppm syringaldehyde, 22.80 ± 1.04 ppm vanillin, 27.06 ± 1.20 ppm p-coumaric acid, and 50.19 ± 2.23 ppm ferulic acid were produced.
Refined palm-pressed mesocarp fibre oil (PPFO), which can be obtained from one of the by-products of palm oil milling, palm-pressed mesocarp fibre, is categorized as palm sludge oil. So far, it has been given less attention and underutilized until some recent scientific reports revealing its high content of phytonutrients, carotenoids and vitamin E, which have been proven scientifically to possess anti-oxidant activity. The study evaluated the stability of PPFO as a carrier for plant-based emulsion. PPFO was extracted and examined for its positional distribution of fatty acids, saturation levels and iodine value (IV) using NMR spectroscopy. The PPFO-based emulsion was then prepared and subjected to stability tests, including temperature variation, centrifuge test, cycle test, pH and slip melting point for 28 days. Phase separation was observed from PPFO-based emulsion stored at 40℃ from day-21 onwards while no creaming found in all the palm olein-based emulsions stored at the three storage temperatures. Nevertheless, results indicated that the PPFO-based emulsion passed all the tests above showing insignificant phase separation (p > 0.05) compared with those of palm olein commonly used in emulsion preparation. The findings suggested that PPFO enriched with valuable phytonutrients could be used as an alternative carrier oil in emulsion formulation, which is an important component in personal care products.
Palm oil production from oil palm (Elaeis guineensis Jacq.) is vital for the economy of Malaysia. As of late, sustainable production of palm oil has been a key focus due to demand by consumer groups, and important progress has been made in establishing standards that promote good agricultural practices that minimize impact on the environment. In line with the industrial goal to build a traceable supply chain, several measures have been implemented to ensure that traceability can be monitored. Although the palm oil supply chain can be highly complex, and achieving full traceability is not an easy task, the industry has to be proactive in developing improved systems that support the existing methods, which rely on recorded information in the supply chain. The Malaysian Palm Oil Board (MPOB) as the custodian of the palm oil industry in Malaysia has taken the initiative to assess and develop technologies that can ensure authenticity and traceability of palm oil in the major supply chains from the point of harvesting all the way to key downstream applications. This review describes the underlying framework related to palm oil geographical traceability using various state-of-the-art analytical techniques, which are also being explored to address adulteration in the global palm oil supply chain.
Biocomposites are materials that are easy to manufacture and environmentally friendly. Sugar palm fibre (SPF) is considered to be an emerging reinforcement candidate that could provide improved mechanical stiffness and strength to the biocomposites. Numerous studies have been recently conducted on sugar palm biocomposites to evaluate their physical, mechanical and thermal properties in various conditions. Sugar palm biocomposites are currently limited to the applications of traditional household products despite their good thermal stability as a prospective substitute candidate for synthetic fibres. Thus, thermal analysis methods such as TGA and DTG are functioned to determine the thermal properties of single fibre sugar palm composites (SPCs) in thermoset and thermoplastic matrix as well as hybrid SPCs. The biocomposites showed a remarkable change considering thermal stability by varying the individual fibre compositions and surface treatments and adding fillers and coupling agents. However, literature that summarises the thermal properties of sugar palm biocomposites is unavailable. Particularly, this comprehensive review paper aims to guide all composite engineers, designers, manufacturers and users on the selection of suitable biopolymers for sugar palm biocomposites for thermal applications, such as heat shields and engine components.
In this study, mannanoligosaccharides (MOS) were isolated from palm kernel cake by aqueous extraction using high temperature and pressure. Structural characterization of MOS was carried out using acid hydrolysis, methylation analysis, ESI-MS/MS and 1D/2D NMR. The prebiotic activity of MOS was evaluated in vitro using two probiotic Lactobacillus strains. Sugar analysis indicated the presence of mannose in each of the oligomers. Methylation and 1D/2D NMR analysis indicated that the MOS have a linear structure consisting of (1→4)-β-d-mannopyranosyl residues. ESI-MS/MS results showed that the isolated mannan oligomers, MOS-III, MOS-IV, MOS-V and MOS-VI consist of tetra-, penta-, hexa-, and hepta-saccharides with molecular weights of 689, 851, 1013 and 1151Da, respectively. Based on the in vitro growth study, MOS-III and MOS-IV was found to be effective in selectively promoting the growth of Lactobacillus reuteri C1 strain as evidenced by the optical density of the culture broth.
The conversion of starchy sago (Metroxylon sagu) pith waste (SPW), a lignocellulosic biomass waste, to fermentable sugars under mild conditions had been successfully demonstrated. The optimum depolymerization of SPW was achieved at 2 wt% sample loading which was catalyzed by 100 mM of oxalic acid in the presence of 25 wt% NaCl solution at 110 °C for 3 h. Up to 97% SPW sample was being converted into fermentable sugars with limited formation of by-products after two sequential depolymerization cycles. Both reaction temperature and concentration of oxalic acid were crucial parameters for the depolymerization of SPW which exhibited a high selectivity for the production of glucose over other reducing sugars.