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Carboxymethyl cellulose (CMC) is a food additive that plays an important role in the structure-forming of most food. The current extraction of CMC from wood has created competition with the wood industries. To ensure the sustainability of CMC, the search for alternatives to wood is critical. A study on the extraction of CMC from oil palm empty fruit bunch (OPEFB) stalk fibres (SCMC) was successfully carried out previously by the authors. In this study, the potential application of SCMC on low-fat ice cream properties was investigated. Liquid ice cream mix with SCMC had a higher viscosity (129.4 cP) when compared to the control sample (25.5 cP). However, the viscosity of liquid ice cream mix produced using SCMC was slightly lower than the one produced using the commercial CMC (360 cP). The overrun of the SCMC low-fat ice cream was slightly lower (35.2%) than the one produced using commercial CMC (41.5%). The resistance of SCMC and commercial CMC low-fat ice creams towards melting were about the same (60.28% and 58.75% respectively). The commercial CMC produced slightly harder (38.19 N) ice cream than the one with SCMC (28.88 N). Thus, the low-fat ice cream produced using SCMC is comparable with the low-fat ice cream produced using commercial CMC. This indicates the reliability of the extracted CMC from OPEFB stalk fibres to be applied in food, and thus creates a complete solution for the utilization of palm oil mill by-product to produce a value-added product.

The issue of food safety is a major concern in the oil palm industry as it will affect national income. 3-MCPD and GE are contaminants formed during the refining of palm oil, mainly in the deodorization step. Palm oil was reported to contain one of the highest levels of these contaminants amongst all vegetable oils. Both 3-MCPD and GE are characterized as a possible risk to human health. This review aimed to provide a comprehensive summary of the 3-MCPD and GE precursors and mitigation strategies to minimize the 3-MCPD and GE formation. Therefore, the oil palm industry should address these issues and find ways to comply with food laws, acts, regulations, and standards enforced by local and international authorities.

The aim of this study was to investigate the functional properties of Tilapia’s fish scale gelatin films with various type of plasticizers. Gelatin film solutions using solution casting method with different type of plasticizers; glycerol, sorbitol, glycerol: sorbitol (80:20), and diethylene glycol with concentration of 30% were stirred at 60 °C for one hour and dried at room temperature for 2 days. The determination of film characterizations was included thermal (thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)), mechanical testing using the Texture Analyzer and chemical properties (Fourier transform infrared spectroscopy (FTIR)). Essentially, all plasticizers show an improvement by able to plasticizing with increasing of elongation at break in between 14 and 50% compared to the gelatin film without plasticizer. Meanwhile, the tensile strength of plasticized gelatin films decreased drastically compared to the unplasticized gelatin film. From the result obtained in TGA analysis, film with sorbitol and dietheylene glycol demonstrated low resistance toward high temperature compared to film with glycerol and glycerol:sorbitol gelatin film. In addition, all the gelatin film with different plasticizers show the value of Tg around 60-70.85 °C except for sorbitol with Tg 79.98 °C due to strong intermolecular chain interaction between the sorbitol and gelatin. FTIR spectrum analysis demonstrated that only gelatin film with glycerol does not have any amide group that related to stretching vibration of carbonyl group along the polypeptide backbone of the plasticized film which later give highest tensile strength. Hence, notable differences of functional properties were found with four different type of plasticizers used in the gelatin film, especially in term of temperature resistance and mechanical properties

Investigation on the effect of starch interface towards mechanical behaviour of rice grains was reported through mechanical tests (compression and three-point bending) and finite element micromechanics model. The model considered starch kernels within the rice grain (for milled rice) as well as a layer of husk on top (for unmilled rice). The interface between the kernels was modelled using cohesive zone model to simulate interfacial damage. Higher fracture stress was reported at lower moisture content from the three-point bending, and linear elastic behaviour was observed from compression tests of milled rice, which was independent of moisture contents. The force-displacement curves of milled rice are linear, whereas unmilled rice showed initial softening before hardening at approximately 0.1 mm displacement. The representative finite element models showed agreement with compression and bending experiments, suggesting significant influence of starch interface damage towards fracture of milled rice grain.

Physicochemical, morphological, rheological characteristics and finite element modelling of wheat flour, rice flour, starch and gluten were studied in this work. The physicochemical analysis of rice flour exhibited almost similar characteristics to wheat flour without gluten present. Rice flour and rice starch contained higher value of carbohydrate and fibres compared to wheat flour and wheat starch. Likewise, rice flour and rice starch interacted strongly with water and oil due to higher value of water absorption, water solubility and oil absorption indices compared to wheat flour and wheat starch. SEM images showed that rice starch had uniform size, smaller polyhedral shape and were closely intact between granules, whereas wheat starch consisted of large and small granules that were sphere and irregular in shapes. Compression tests conducted on all the doughs showed viscoelastic behaviour and permanent set. Stress-strain curve of rice starch-gluten dough are shown to be higher than wheat starch-gluten dough. Oscillation tests conducted on all doughs showed larger storage than loss modulus, indicating more elastic than viscous behaviour of the doughs. Finally, finite element model using ‘chess’ geometry for starch and gluten was able to simulate deformation of starch-gluten dough.

A large volume of oil palm empty fruit bunch (EFB) is generated as waste feedstock around the globe. This abundant waste containing 0.75% oil on average could be a promising feedstock for biodiesel production if oil recovery could be accomplished in an economically-viable and environmentally-friendly manner. To achieve that, a new method called High Pressure Water Spray (HPWS) system was introduced and performed by spraying pressurized water (500 psi) at 30 °C, 60 °C, and 90 °C and combination of water-steam at 120 °C and 150 °C onto the surface of the oil palm empty fruit bunches (EFB). The results obtained indicated that, the highest oil removal yield of 94.41 ± 0.02 wt% was obtained at 150 °C. Moreover, bioprospection of biodiesel properties based on fatty acid methyl ester (FAME) profile revealed that the biodiesels produced from the fresh crude palm oil and residual oil were comparable and were in accordance with international standards. In addition to that, the HPWS process led to an enhanced quality of the remaining lignocellulosic materials for conversion into other value added bio-products such as ligno-ethanol by decreasing lignin content and increasing cellulose content. In view of environmental impact assessment, the HPWS system showed favorable impacts on all the end-point damage categories especially in resources damage category. Moreover, economic assessment showed that the recovered CPO could be generated at a low price of USD 0.41 vs. USD 0.66 for CPO. Overall, this process could drastically increase the market value of an abundant type of waste in many parts of the world, i.e., EFB leading to the generation of additional wealth for the palm oil industry.

The heterogeneous lignocellulosic contents of oil palm empty fruit bunch (OPEFB) fiber requires the use of chemical or biological pre-treatment for further value-added applications. An effective biological pre-treatment was preferred since it is mild, low energy, substrate specific and will not generate any inhibitory chemicals that interfere enzymatic activities and fermentation process. The biological pre-treatment of OPEFB fibers by local isolate Pycnoporus sanguineus was investigated in this work to improve its biodegradability through laccase production via solid-state fermentation approach. The effects of physical parameters (temperature, inducer concentrations, substrate loading) were explored to obtain maximum laccase production by P. sanguines. Results showed that the use of extractive-free OPEFB fiber at 30 °C supplemented with 4 mM of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 10 g of OPEFB loading yielded laccase production that was 2.1 fold higher compared to raw OPEFB. The changes of chemical and surface structures of raw, chemicals and laccase treated OPEFB were reported from Fourier-transform infrared spectroscopy (FTIR), thermogravimetric (TGA) and scanning electron microscopy (SEM) analyses. The simulated techno-economic analysis suggested economic feasibility of a batch bio-refinery for laccase production in an industrial scale feed at a maximum rate of 50 tons OPEFB/batch. From the simulated baseline study, the cost price forecast for laccase production was 14.26 US$/kg owing to the capital (65.87%) and raw materials costs (31.68%). This study reveals the potential of P. sanguineus to be used not only in biorefinery industry but also in biopulping, biobleaching (in textile and paper industries) and degrading phenolic waste (dye, colorant, pesticide waste).

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.

The current extraction of carboxymethyl cellulose (CMC) from wood has created competition with wood industries. Interest in alternative sources is critical to ensure the sustainable production of CMC. Therefore, the extraction of CMC from oil palm empty fruit bunch (OPEFB) stalk fibres was evaluated. CMC extracted from OPEFB stalk fibres was characterized for chemical composition as well as by spectroscopic, microscopic, physicochemical, and rheological tests. Highest cellulose content was obtained from raw stalk fibres with the least amount of lignin and residual oil as compared to the empty fruit bunch (EFB) and spikelet. The XRD analysis revealed that the native cellulose was transformed into an amorphous phase, as evidenced from the characteristic peaks that had almost disappeared. Likewise, the FTIR analysis showed that major peaks in the lignin and hemicellulose were absent, which enabled the cellulose to be converted to CMC. Microscopy analysis showed notable changes in the fibres’ morphology throughout the extraction process. In addition, X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), physicochemical studies, and rheological tests on extracted CMC showed that there was a significant difference between each phase of the extraction process and this showed that OPEFB stalk fibre was feasible to produce CMC that was comparable to those of commercial CMC.

Experimental and numerical investigation was conducted to study the micromechanics of oil palm empty fruit bunch fibres containing silica bodies. The finite viscoelastic-plastic material model called Parallel Rheological Network model was proposed, that fitted well with cyclic and stress relaxation tensile tests of the fibres. Representative volume element and microstructure models were developed using finite element method, where the models information was obtained from microscopy and X-ray micro-tomography analyses. Simulation results showed that difference of the fibres model with silica bodies and those without ones is larger under shear than compression and tension. However, in comparison to geometrical effect (i.e. silica bodies), it is suggested that ultrastructure components of the fibres (modelled using finite viscoelastic-plastic model) is responsible for the complex mechanical behaviour of oil palm fibres. This can be due to cellulose, hemicellulose and lignin components and the interface behaviour, as reported on other lignocellulosic materials.

The mechanical behaviour of dough, gluten and starch were studied in an effort to investigate whether bread dough can be treated as a two phase (starch and gluten) composite material. Mechanical loading tests revealed rate dependent behaviour for both the starch and gluten constituents of dough. There is evidence from cryo-Scanning Electron Microscopy (SEM) that damage in the form of debonding between starch and gluten occurs when the sample is stretched. In addition, a reasonable agreement is seen between the Lodge material model and the compression test data only, indicating again that possibly ‘damage’ is essentially debonding which does not occur under compression, unlike tension and shear loading. A composite finite element model was developed using starch as filler and gluten as matrix. The interface between the starch and gluten was modelled as a cohesive contact interaction. When the interaction of starch and gluten is strong, as indicated for the dough with no damage, the stress-strain curve is always higher than the gluten stress-strain curve under both tension and shear loading. In contrast, when damage is activated in the form of debonding, the dough stress-strain curves under tension are seen to cross over the curves for gluten and therefore leading to lower stress values than in gluten. No damage/debonding occurs under compression when a damage function is used which is in good agreement with the experimental data.

The effect of alkali pre-treatment (sodium hydroxide, NaOH) on the microstructural, mechanical, and chemical composition of oil palm stalk fibres (OPSF) is reported for future bioconversion processes. The OPSF was pre-treated with various concentrations of NaOH (5, 10, 20, 30, and 40% w/v). Scanning electron microscopy analysis revealed that 5% w/v alkali concentration caused complete removal of silica bodies and waxy layers, whereas pronounced degradation of the fibres occurred at 40% w/v NaOH concentration. Mechanical test results showed that the maximum elastic modulus of untreated OPSF was 2.5 GPa and the modulus was not sensitive to alkali concentration. Permanent set (plastic strain) and viscoelastic behaviours of OPSF were observed from the loading-unloading and stress relaxation test results, respectively. Agreement was observed between the Prony series viscoelastic model and test results, which provided further evidence of the viscoelastic behaviour of OPSF.

The mechanical behavior of dough, gluten, and starch was studied in an effort to investigate whether bread dough can be treated as a two phase (starch and gluten) composite material. Mechanical loading tests revealed rate-dependent behavior for both the starch and the gluten constituents of dough. There is evidence from cryo-scanning electron microscopy that damage in the form of debonding between starch and gluten occurs when the sample is stretched. In addition, the Lodge material model was found to deviate from the tension and shear stress-strain test data by a considerably larger amount than from the compression test data. This could indicate that “damage” is dominant along the gluten-starch interface, causing debonding; the latter occurs less under compression loading, but is more prevalent in tension and shear loading. A single-particle finite element model was developed using starch as a filler contained in a gluten matrix. The interface between starch and gluten was modeled using cohesive zone elements with damage/debonding occurring under opening/tension and sliding/shear modes. The numerical results are compared to experimental stress-strain data obtained at various loading conditions. A comparison of stress-strain curves obtained from 2D and 3D single-particle models and a 2D multiparticle model led to good agreement, indicating that the single-particle model can be used to adequately represent the microstructure of the dough studied here.

The mechanical behaviour of dough and gluten was studied in an effort to investigate whether bread dough can be treated as a two phase (starch and gluten) composite material. The dough and gluten show rate dependent behaviour under tension, compression and shear tests, and non-linear unloading-reloading curves under cyclic compression tests. There is evidence from cryo-Scanning Electron Microscopy (SEM) that damage in the form of debonding between starch and gluten occurs when the sample is stretched. A composite finite element model was developed using starch as filler and gluten as matrix. The interaction between the starch and gluten was modelled as cohesive contact. The finite element analysis predictions agree with trends seen in experimental test data on dough and gluten, further evidence that debonding of starch and gluten is a possible damage mechanism in dough.