Papers by ida idayu muhamad
Jurnal Teknologi, 2014
Vitamin E is essential in the human body which naturally found in vegetable fats and oil and thei... more Vitamin E is essential in the human body which naturally found in vegetable fats and oil and their derived products. Several palm-based oils obtained from palm oil mills and refineries were revised in this paper as the raw material for vitamin E. Tocopherols and tocotrienols isomers of the vitamin E content are found nearly comparable with crude palm oil. To obtain the tocopherols and tocotrienols, various developed technologies for the extraction were also reviewed. These include the solvent-based extraction, chemical modification, adsorption, enzymatic process, molecular distillation, microwave-assisted extraction and membrane technology. Each of the technologies has the advantages as well as limitations. Therefore, process design and selection for the chosen technology are crucial in order to determine recovery of vitamin E obtained, time efficiency, cost effectiveness, safety of products and environmentally friendly impacts. A green technology approach could be further diversifi...
Biopolymer active packaging is known to have low mechanical strength and highly brittle. Regardle... more Biopolymer active packaging is known to have low mechanical strength and highly brittle. Regardless to its disadvantage,
polymers from natural sources have attracted serious attention since the non-renewable sources for example petroleum, the major precursor of plastic manufacturing become depleted. Starch-Chitosan for instance is a hybrid film that entirely green as it produced from a renewable material and totally degradable. The addition of chitosan in film packaging able to kill pathogen hence increases the food shelf life. Through nanotechnology advance, nanomaterial can be used for material reinforcement. Nowadays, greener approach could be applied by incorporating natural cellulose nanofiber into the film matrix. Oil palm empty fruit bunch (OPEFB) fiber that rich of cellulose contents could be treated chemically to purify the cellulose in the fiber. Cellulose fiber obtained was cut to a nano-size using acid hydrolysis. Transmission Electron Microscopy (T.E.M) obtained shown the nanofiber size was ranged between 1-100nm in diameter. Nanocomposite film formulation, was constructed by varying the cellulose nanofiber incorporation between 2-10% per weight of starch. The strength of the films was measured as well as antimicrobial properties. The addition of 2% cellulose nanofiber into the film matrix exhibits high tensile strength with 5.25Mpa compared to starch-chitosan hybrid distinguished beyond that film with 3.96Mpa. However, no significant improvement in tensile strength was
ratio. Antimicrobial analysis shows that the addition of cellulose nanofiber could increase the inhibition effect towards gram-positive bacteria but not towards gram-negative bacteria. The addition of 2% cellulose nanofiber increased the inhibition diameter towards gram positive bacteria, Bacillus subtilis up to 33%. However, inhibition towards Bacillus subtilis decreased with the incorporation of more cellulose nanofiber. In gram-negative bacteria Escherichia coli, theaddition of cellulose nanofiber does not give significant effect to bacterial. In General, the addition of the unique structure of cellulose nanofiber in the starch based polymer system could enhance the mechanical strength of the film and increase the inhibition of the gram positive bacteria.
In general, starch-based biopolymer has low mechanical properties. Hence, various methods have be... more In general, starch-based biopolymer has low mechanical properties. Hence, various methods have been applied to enhance its properties as well as the incorporation of fibrous nanocellulose. The aim of this study is to enhance the mechanical properties of starch-based polymer by incorporating nanocellulose extracted from oil palm empty fruit bunch. The cellulose nanofibre was obtained by hydrolysing oil palm empty fruit bunch fibre with 64% sulphuric acid at 45°C for 90 minutes. It has diameter between 50 and 90 nm as shown by transmission electron microscopy image. In nanoreinforced starch-based packaging, the amount of nanocellulose loading was varied between 2 and 10% per weight of starch. The tensile strength of 2% cellulose nanofibre incorporated film was increased to 4·68 MPa, which is 28% higher than the tensile strength exhibited by the native starch-based film, 3·66 MPa. However, the tensile strength was reduced when cellulose nanofibre incorporation goes beyond 2%. The Young's modulus demonstrates the same pattern as tensile strength, where 2% of cellulose nanofibre gave the optimum results for Young's modulus value. Elongation percentage of nanobiocomposite film also reduced even at low cellulose nanofibre loading, 2%. Regardless of its drawback on elongation percentage, an addition of 2% of cellulose nanofibre is the finest ratio that could improve the mechanical properties of starch-based biopolymer.
Wheat flour milling involves repeated breakage (by roller milling) and separation (by sifting) of... more Wheat flour milling involves repeated breakage (by roller milling) and separation (by sifting) of flour particles to give efficient recovery of fine flour relatively free from bran contamination. A starting point for modelling the behaviour of mixtures of wheat kernels is to be able to measure the variation in kernel properties within the mixture. The Perten Single Kernel Characterisation System (SKCS) gives the distributions of kernel mass, moisture content, diameter and hardness within a mixture, from 300 kernels within 5 minutes. A challenge remains to relate these measured distributions to predictions of milling performance. To this end, a breakage function in terms of these measured parameters for individual kernels has been constructed, and integrated over the distribution of kernel properties using the breakage equation. These models allow prediction of the output particle size distribution delivered by First Break roller milling of kernels varying in size, hardness and variety, based entirely on SKCS characteristics. Predictions have been developed for both sharp-to-sharp and dull-to-dull roll dispositions, and show encouraging agreement with independent data.
Benzyl diethyldithiocarbamate is immobilized on a composite bacterial cellulosechitosan membrane ... more Benzyl diethyldithiocarbamate is immobilized on a composite bacterial cellulosechitosan membrane via a silane coupler. This treated membrane is grafted with theophylline-imprinted copolymer of methacrylic acid and ethylene glycol dimethacrylate by ultraviolet irradiation. The highest degree of grafting obtained is 0.3334% for r (weight ratio of monomers to bacterial cellulose-chitosan membrane) equal to 3.244 in mmol/ml. The synthesized membrane is prepared by using 0.5% chitosan solution containing 15.0% PEG and evaporating the solution for 2.5 hour after coating at room temperature. The relative flux of 3.69 L/m 2 .h at 12.5 bar is obtained. The average pore diameters are 135 Å in dry state and 404 Å in wet state. The chitosan and polyethylene glycol contents have a significant effect on membrane porosity and the flow rate of water through the membrane. The membrane tensile strength is larger than the plain bacterial cellulose support, in both wet and dry states.
This study was conducted to develop the method of extracting beta-glucan from the fiber of Elaeis... more This study was conducted to develop the method of extracting beta-glucan from the fiber of Elaeis guineensis or oil palm trunk (OPT) and to evaluate its potential. From the previous studies, beta-glucan usually extracted from barley, oats and also bacteria. In this research, wet separation method which is also known as aqueous alcohol method was used to extract beta-glucan from the oil palm trunk fiber. This indirect method of producing beta-glucan was found optimized at conditions of 50% of ethanol as solvent, 4 hours pretreatment duration and temperature of 70ºC. Finally beta-glucan was analyzed by enzymatic method and the percentage of beta-glucan extracted in this study was 34.17 percent.
Capsaicinoid, a naturally occurring alkaloid group and active components which can be found in ch... more Capsaicinoid, a naturally occurring alkaloid group and active components which can be found in chili peppers variety (Capsicum spp.), contributes to the pungency, taste, and aroma of chili peppers. Apart from their culinary and medicinal properties, capsaicinoid functions as antioxidant agent in food preservation. In the current research, the evaluation of bio-active substance of capsaicinoid was carried out to determine its potential in development of antimicrobial film for packaging. A mixture of acetone: petroleum ether (1:1) had been used in extracting the capsaicinoids and carotenoids (natural red pigment).The four types of chili pepper studied were Green Malagueta Salvador, Red Malagueta Salvador, red Thai Capsicum Frutescens and red Cayenne. The optimum capsaicinoids extraction time and amount of carotenoids (color intensity) for each variety of chili peppers were studied. Lastly, antimicrobial properties of AM films were determined as they inhibited both gram-positive (Streptococcus and B. subtilis) and gram-negative (E. coli) bacteria successfully through agar diffusion test and liquid culture test.
The perah seed oil is a potential source for high unsaturated and omega 3 oil. It can be an alter... more The perah seed oil is a potential source for high unsaturated and omega 3 oil. It can be an alternative choice for regular vegetable oil. The chemical and physical properties need to be investigated and evaluated for it to be used feasibly in the food industries and health care products. Modern day's faster and sophisticated instruments and techniques are used to evaluate the physicochemical properties of edible or vegetable oils. This study includes FTIR spectroscopy GC-MS and GC to evaluate the chemical properties of it while colour was used to study the physical property. The peaks by FTIR were found at 3300-3000 cm -1 , 2960 2850 cm -1 , 1760 1670 cm -1 , 1650 1580 cm -1 , and 1340 1020 cm -1
The nutritional and antinutritional value of fresh and fermented perah seed were studied. The col... more The nutritional and antinutritional value of fresh and fermented perah seed were studied. The colour of fermented perah seed changed from beige into dark brown and strong pleasant smell was developed. From proximate analysis, fermented perah seed contained lower moisture, protein, fiber and ash compare to fresh perah seed. Interestingly, the fat content increased after fermentation process for about 9%. On the other hand, about consistent protein content was retained after fermentation process resulted in less than 4% from fresh perah seed. In comparison with other types of seeds, perah seed shows relatively high content in protein (59%) and fiber (77%). Mineral analysis showed a reduced amount of heavy metal in perah after fermentation compare to fresh seed. Meanwhile, antinutritional analysis found very insignificant untraceable presence of cyanide in both types of the seeds. Therefore, it can be concluded that traditional practice of fermenting perah seed before consumption is indeed practical to retain optimum nutrition content, prolonged shelf life with seven times lower moisture content also reduction in cyanide traces and heavy metals compared to the fresh perah seed.
Microwave vacuum and convective hot air dehydration of jackfruit (Artocarpus Heterophyllus) bulbs... more Microwave vacuum and convective hot air dehydration of jackfruit (Artocarpus Heterophyllus) bulbs were carried out to study the effects of different dehydration treatments on drying characteristics, rehydration ability and quality attributes. Jackfruit bulbs were dehydrated by microwave power output of 58, 140, 220, and 321W respectively combined with vacuum level of -65 cmHg during microwave vacuum dehydration. Convective hot air dehydration was also conducted with the hot air temperature of 60, 70, and 80°C, respectively. Microwave vacuum dehydration with microwave power output of 321 W resulted in 133 times faster in drying time compared to convective hot air dehydration with hot air temperature of 60°C. All dehydration data were subjected to Newton and Page's equation model fitting, where Page's equation model was well fitted for all dehydration conditions with R 2 > 0.994. Furthermore, microwave vacuum dehydration produced better quality of dehydrated jackfruit bulbs with higher rehydration ability and sensory attributes.
The aim of this study was to evaluate the effects of palm olein (PO) addition on the thermooxidat... more The aim of this study was to evaluate the effects of palm olein (PO) addition on the thermooxidative degradation of canola oil (CO) during frying of potato pieces at 185 5C. The blends were prepared in the volume ratios of 20:80 (PO:CO, PC1) and 40:60 (PO:CO, PC2). Refractive index, free fatty acid content, peroxide value, p-anisidine value, total oxidation value, viscosity, specific extinction, polymer content, polar compounds, food oil sensor value and color of the oils all increased, whereas iodine value and C 18.2 /C 16:0 ratio decreased as frying progressed. The percentage of linoleic and linolenic acids tended to decrease, whereas the percentage of palmitic, stearic and oleic acids, increased. In DSC analysis, addition of PO to CO altered the shapes of endo-or exotherm peaks of CO and became sharp; might be due to the change in fatty acid composition. Based on the most oxidative stability criteria investigated, it could be concluded that the frying process caused the formation of comparatively lower amounts of oxidation products in the blends compared to CO, indicating a lower extent of thermooxidative degradation of the blends. However, higher amounts of free fatty acids and higher color units were both detected in the blends compared to pure CO at the end of frying trial. It appeared that proper blending of highly unsaturated CO with PO could result in oil blends which could meet nutritional needs with improved stability for domestic cooking and deep-frying.
Polyacrylamide based hydrogel was synthesized using sodium carboxymethylcellulose (NaCMC). N,N'-M... more Polyacrylamide based hydrogel was synthesized using sodium carboxymethylcellulose (NaCMC). N,N'-Methylenebisacrylamide (MBA) as cross-linker, ammonium persulfate (APS) and N,N,N',N'-tetra-methylethylenediamine (TEMED) as initiators. Magnesium oxide (MgO) nanoparticles were added to the hydrogel network to investigate the antibacterial activity of synthesized polymer. Hydrogels were characterized using Fourier Transform Infrared Spectroscopy (FTIR), and Field Emission Scanning Electron Microscope (FESEM). The physical and chemical characterizations of the prepared hydrogels give valuable information on the morphological structure of polymer, swelling behavior, bonding formation of gels and physical properties. The incorporation of NaCMC enhanced the hydrogel properties physically and chemically in the aspects of swelling capacity, strength and flexibility. This study also investigated the antibacterial activities of prepared hydrogels against Escherichia coli which is a Gram negative food pathogenic bacteria. For this purpose, agar diffusion test or agar plate test was carried out and inhibition area for each hydrogel was determined. Polyacrylamide hydrogel with NaCMCshowed a lowinhibition zone towards E. coli. However, interestingly, the addition of 0.03 gram of MgO nanoparticles into the hydrogel network resulted in about triple inhibitionstrength relatively.
This study involved the extraction of rubber (Hevea brasiliensis) seed oil using supercritical ca... more This study involved the extraction of rubber (Hevea brasiliensis) seed oil using supercritical carbon dioxide and Soxhlet techniques. The main aim of this study is to compare the extraction method between SC-CO 2 and Soxhlet extraction. The arrays of operating parameters for supercritical carbon dioxide are temperature and pressure conducted at 40°C, 60°C and 80°C and 20MPa, 25MPa and 30MPa respectively. The extraction was also processed under dynamic condition of 180min and carbon dioxide at constant flow rate of 4mL/min. The parameters studied for Soxhlet extraction are due to different solvents and extraction time.
Antimicrobial (AM) packaging incorporated with pH indicator is a promising form of smart food pac... more Antimicrobial (AM) packaging incorporated with pH indicator is a promising form of smart food packaging with great potential; economically, environmentally and increase biosafety of packed food. An AM Smart Packaging is made by incorporating suitable AM agents into food package matrices and applying a bio switch concept to inhibit the spoilage and the pathogenic microorganisms for the safety of food. The value-added pH indicator system will be used to monitor the condition of packaged foods to give information about the chemical-microbiological quality of the packaged food during transport and storage. The main objective of this study was to develop the formulation of AM starch-based film in which the active compound, thymol was incorporated into the polymeric material. A solution casting method was used in the film preparation and thymol was incorporated prior to casting. The physical and chemical characterizations of the prepared film gave valuable information on moisture content and chemical composition of the films. The AM film had a relatively smoother, cleaner and more compact surfaces compared to the control film. The resultant film with reduction in moisture content was used to indicate the relationship between thymol and water molecules in the diffusion mechanism throughout the film matrices. FTIR analysis implied the consistency of the chemical composition and structure of the AM film compared to the control film indicating that the addition of thymol into the film did not affect or alter the carbonyl functional groups and stability of the film.
Bacterial cellulose is a pure and highly hydrophilic material with high mechanical strength. Furt... more Bacterial cellulose is a pure and highly hydrophilic material with high mechanical strength. Furthermore by adding certain substrates or by manipulating the operating conditions it is possible to change the properties of the bacterial cellulose. The objective of this research is to develop a modified method for fabrication of bacterial cellulose-polyaniline films. Polyaniline was incorporated into bacterial cellulose during fermentation by Acetobacter xylinum in order to produce conductive film. Bacterial cellulose/polyaniline film was synthesized with addition of polyaniline in Rotary-discs reactor during bacterial cellulose formation. The conductivity of film produced was measured and compared. The effects of polyaniline concentration were studied and the relationship between polyaniline concentration and film conductivity were determined.
Innovative Food Science & Emerging Technologies, 2004
The particle size distribution (psd) produced by breakage of wheat in the Perten Single Kernel Ch... more The particle size distribution (psd) produced by breakage of wheat in the Perten Single Kernel Characterisation System (SKCS) was measured using sonic sifting, for a range of wheat varieties, kernel sizes and moisture contents. At moisture contents of 16% wb, the psd produced by the SKCS was very evenly spread over the range 106-3350 mm, with the average particle size much greater than would result from roller milling. Hard wheats gave slightly smaller average particle sizes in the broken material (this was unexpected and contrasts with First Break roller milling, for which hard wheats give larger output particles than soft wheats), but the variation in psd among different wheat varieties was surprisingly small. This indicates that the SKCS exerts a very positive breakage action on wheat grains, giving similar degrees of breakage to kernels of different hardness. The reported hardness index therefore depends primarily on the crushing force profile or energy to grind, and is not confounded by differences in the extent of breakage achieved. Kernel size similarly gave little difference in the output psd. The effect of increasing the moisture content from 9 to 17% wb was to increase the average output particle size greatly; moist kernels do not break so readily in the SKCS. ᮊ Industrial relevance: There is an emerging trend towards single kernel characterization in wheat quality testing to also gain insights on genetic and environmental influences as well as on moisture distribution. Several attempts have been made to approximate hardness as a key quality criterion. However, no universally accepted definition of hardness exists. This paper is based on the notion that during First Break roller milling, kernels break independently according to their individual properties. Meaning if the distribution of kernel properties in a sample is known predictions for the breakage behavior of grain mixtures should be possible. Interestingly it could be shown that hardness was independent of moisture content (9-17%). Hardness measurement under the given conditions related primarily to the energy required to crush the kernels. This work clearly addresses the industrial need for a fundamental definition of wheat hardness.
Malaysian Polymer Journal (MPJ …, Jan 1, 2006
The hydrolytic degradation of poly-β-(hydroxybutyrate) PHB, poly-β-(hydroxybutyrate-co-β-valerate... more The hydrolytic degradation of poly-β-(hydroxybutyrate) PHB, poly-β-(hydroxybutyrate-co-β-valerate) (PHBV) and PHBV/cellulose triacetate blend was studied under different pH at 37 °C. PHBV showed a similar trend of degradation to PHB but at higher rates in alkaline medium. The presence of cellulose triacetate in the blend increased the water uptake and permeability which favoured the hydrolytic degradation especially in lower pH medium. In the surface hydrolysis of PHB and its blends, the overall degradation rate was increased with higher pH values. The melting temperature, crystallinity and tensile properties were also determined. The blend, PHBV/CTAc had the lowest crystallinity values and PHB had the highest. However, the blends were mechanically better in strength and toughness.
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Papers by ida idayu muhamad
polymers from natural sources have attracted serious attention since the non-renewable sources for example petroleum, the major precursor of plastic manufacturing become depleted. Starch-Chitosan for instance is a hybrid film that entirely green as it produced from a renewable material and totally degradable. The addition of chitosan in film packaging able to kill pathogen hence increases the food shelf life. Through nanotechnology advance, nanomaterial can be used for material reinforcement. Nowadays, greener approach could be applied by incorporating natural cellulose nanofiber into the film matrix. Oil palm empty fruit bunch (OPEFB) fiber that rich of cellulose contents could be treated chemically to purify the cellulose in the fiber. Cellulose fiber obtained was cut to a nano-size using acid hydrolysis. Transmission Electron Microscopy (T.E.M) obtained shown the nanofiber size was ranged between 1-100nm in diameter. Nanocomposite film formulation, was constructed by varying the cellulose nanofiber incorporation between 2-10% per weight of starch. The strength of the films was measured as well as antimicrobial properties. The addition of 2% cellulose nanofiber into the film matrix exhibits high tensile strength with 5.25Mpa compared to starch-chitosan hybrid distinguished beyond that film with 3.96Mpa. However, no significant improvement in tensile strength was
ratio. Antimicrobial analysis shows that the addition of cellulose nanofiber could increase the inhibition effect towards gram-positive bacteria but not towards gram-negative bacteria. The addition of 2% cellulose nanofiber increased the inhibition diameter towards gram positive bacteria, Bacillus subtilis up to 33%. However, inhibition towards Bacillus subtilis decreased with the incorporation of more cellulose nanofiber. In gram-negative bacteria Escherichia coli, theaddition of cellulose nanofiber does not give significant effect to bacterial. In General, the addition of the unique structure of cellulose nanofiber in the starch based polymer system could enhance the mechanical strength of the film and increase the inhibition of the gram positive bacteria.
polymers from natural sources have attracted serious attention since the non-renewable sources for example petroleum, the major precursor of plastic manufacturing become depleted. Starch-Chitosan for instance is a hybrid film that entirely green as it produced from a renewable material and totally degradable. The addition of chitosan in film packaging able to kill pathogen hence increases the food shelf life. Through nanotechnology advance, nanomaterial can be used for material reinforcement. Nowadays, greener approach could be applied by incorporating natural cellulose nanofiber into the film matrix. Oil palm empty fruit bunch (OPEFB) fiber that rich of cellulose contents could be treated chemically to purify the cellulose in the fiber. Cellulose fiber obtained was cut to a nano-size using acid hydrolysis. Transmission Electron Microscopy (T.E.M) obtained shown the nanofiber size was ranged between 1-100nm in diameter. Nanocomposite film formulation, was constructed by varying the cellulose nanofiber incorporation between 2-10% per weight of starch. The strength of the films was measured as well as antimicrobial properties. The addition of 2% cellulose nanofiber into the film matrix exhibits high tensile strength with 5.25Mpa compared to starch-chitosan hybrid distinguished beyond that film with 3.96Mpa. However, no significant improvement in tensile strength was
ratio. Antimicrobial analysis shows that the addition of cellulose nanofiber could increase the inhibition effect towards gram-positive bacteria but not towards gram-negative bacteria. The addition of 2% cellulose nanofiber increased the inhibition diameter towards gram positive bacteria, Bacillus subtilis up to 33%. However, inhibition towards Bacillus subtilis decreased with the incorporation of more cellulose nanofiber. In gram-negative bacteria Escherichia coli, theaddition of cellulose nanofiber does not give significant effect to bacterial. In General, the addition of the unique structure of cellulose nanofiber in the starch based polymer system could enhance the mechanical strength of the film and increase the inhibition of the gram positive bacteria.