Advanced Materials Research Vol. 1113

Abstract: Particles formations of ginger rhizome were successfully produced by using Rapid expansion supercritical solution (RESS). In this study, effect of extraction temperature (40,45,55 and 65 °C) and constant extraction pressure 4000 Psi were investigated on the particle size of the produced particles. Based on the different experimental conditions, the smallest particle size of ginger after processing via the RESS process was obtained at extraction temperature of 40 °C and extraction pressure, 4000 Psi. Temperature is the one factor that can affect the average particle size of the solid oil particle. The size of the ginger particles were monitored by scanning electron microscopy (SEM).

Abstract: Solubility of carbamazepine co-crystal produced from cooling co-crystallization process with succinic acid as a co-crystal former is investigated in this study. Two techniques were used to determine the solubility of the co-crystal which are gravimetry and HPLC. The solubility experiments in ethanol solvent systems were conducted at 6 different temperatures (25, 30, 35, 40, 45 and 50 °C) while for succinic acid ethanolic solution system were conducted at 5 different concentration ratios. Both of the systems are equilibrated for 72 hours. Result from the experiments has shown that the solubility of co-crystal is temperature dependent. As the temperature increases, the solubility of co-crystal also increases; this agrees with the Second Law of Thermodynamic which states that heat facilitates the dissolution process by providing more energy to the system.

Abstract: The solubility of CO₂ in water and aqueous solutions of NaCl, KCl, CaCl₂, NaCl+KCl (weight ratio= 1:1), NaCl+CaCl₂ (weight ratio= 1:1), KCl+CaCl₂ (weight ratio= 1:1) and NaCl+KCl+CaCl₂ (weight ratio= 1:1:1) was determined experimentally at 35, 45 and 55°C up to 16 MPa and the concentration of the salt was up to 14.3 wt% while in simulation the salt ions of Na⁺, K⁺, Ca²⁺, and Cl^- was determined at wide temperature-pressure-ionic strength range (273 to 533 K, from 0 to 2000 bar, and from 0 to 4.5 molality of salts). Based on experiment data, the solubility increased with increase in pressure but decreased with increasing the temperature and salt concentration. Meanwhile, the model also predicted the CO₂ solubility in seawater at two phase coexistence (vapour-liquid or liquid-vapor) and at three-phase coexistence (CO₂ hydrate-liquid water-vapor CO₂).

Abstract: Cassava starch nanocrystals (CSN) has not been reported in open literature, although other starches such as rice, corn, potato and bean were widely used as the main material. Thus, the objective of this research was to investigate the possibility of synthesizing high yield of CSN at different concentration of sulphuric acid (H₂SO₄). The physical and chemical properties of synthesize CSN was also investigated. Synthesized CSN was prepared by hydrolysing native cassava starch (NCS) with several concentration of H₂SO₄ (2.8 M, 3.0 M, 3.2 M and 3.4 M). The acid hydrolysis process took five days with continuous stirring speed of 300 to 400 rpm, with constant temperature of 37 °C. The hydrolysed solution of CSN underwent centrifuging process with distilled water until neutral to make sure that no acid residues remain in the CSN solution. The CSN precipitate was dried in an oven over night at 60 °C. The highest yield (1.1 %) produced was from 3.4 M CSN. Morphology test by Transmission Electron Microscopy indicated that the samples have been destructed and degraded to be nanocrystals with a size range of 5 - 20 nm. X-ray Diffraction (XRD) and ¹³C Nuclear Magnetic Resonance (NMR) were used to indicate the type of crystallinity for both NCS and CSN.

Abstract: Cocoa butter (CB) is an important major constituent of chocolate and other confectionary products. Several factors such as premium price, uncertainty in supply and variability in quality, have led the search for an alternative such as cocoa butter equivalent (CBE) from available and cheap commercial oils or fats. The aim of this research was to produce CBEs which contain omega-3 and omega-6 by blending hard palm oil mid-fraction (PMF) with canola oil. The reaction was performed by using Lipozyme RM IM as the biocatalyst. It aims to retain omega-3 and omega-6 content in CBE after interesterification. The effect of lipase load (LL), time reaction (TR) and stearic acid (ST) on CBE properties were studied to produce nearly similar CBE properties to CB. The best reaction conditions for maximizing POS (palmitic-oleic-stearic), SOS (stearic-oleic-stearic), and SMP (slip melting point) value while minimizing POP (palmitic-oleic-palmitic) and the levels of diacylglycerol (DAG) formation were; LL, 7.5% (w/w); TR, 8 hours; ST, with 44% stearic acid addition. Omega-3 (5.35%) and omega-6 (1.97%) content in CBE (after interesterification) were not significantly different (p > 0.05) to omega-3 (5.71%) and omega-6 (2.16%) content in initial mixture (before interesterification). The properties of CBE which include POP, POS, SOS, DAG and SMP values were 30.33%, 17.53%, 3.26%, 6.75%, and 46.45°C, respectively under these conditions.

Abstract: Tar removal from producer gas was investigated using activated carbon supported iron catalyst. Activated carbon was derived from jute stick biomass. The catalyst surface areas and pore volume were characterized by using iodiometric titration which shows that as the iron loading percentage increased, the adsorption capability was also increased which represents the increment of pore volume of the catalyst. Based on XRD pattern, the iron species formed on the activated carbon surface is mostly amorphous magnetite (Fe₃O₄) species coexisted with the reduced irons (α-Fe and γ-Fe). The reduced iron on catalyst surface justify the active phase which enhances the tar reforming during biomass gasification.

Abstract: Bedak sejuk, is a traditional cosmetic product that still being used and fond by many women in Malaysia. It is produced by the traditional methods that passed from generation to generation. Rice grains were soaked in water at least for three months or until it fully dissolved. The aim of the study is to determine the effects of soaking on rice granules for bedak sejuk production. Local rice grains (Indica) were soaked in water at ratio of 1:1 (w/v) in a container with lid for 42 days and the water were changed at 14 days interval. The soaking process was a series of batch process. A growth profile of microbial in the fermented supernatant showed that the lag phase started on day 3 of soaking process and the exponential phase started on day 8 of soaking process. The final pH value of fermented supernatant was 4.04 while the final titratable acidity which is expressed as lactic acid was 0.62 mg mL^-1. Reducing sugar increased while total starch decreased during the soaking process. For particle size distribution of rice granules, there is no clear differences in the size distribution but there is slight changes of weight fraction of the rice granules. The analysis of fermented supernatant suggests that natural fermentation occurred during the soaking process while the analysis of rice granules suggests that hydrolysis of rice starch occurred during the natural fermentation process.

Abstract: The purpose of this study is to investigate the antioxidant properties and total phenolic content in local fruit wastes. Watermelon rinds, mango and banana peels were selected in the experiment. Two parameters involved were the extraction time and temperature. All samples had undergone drying process in an oven at 40°C for 24 hours before being extracted with 80%, v/v methanol on a hot plate together with magnetic stirrer. The extraction time was ranged from 20 to 40 minutes and the extraction temperature was from 30 to 60°C. Ferric Reducing Antioxidant Power (FRAP) assay and Folin-Ciocalteu reagent were used for antioxidant analysis and phenolic content determination, respectively. UV-Vis spectrophotometer was used to detect the antioxidant activity at 593 nm and 765 nm for phenolic content. Response Surface Method was used to find the best extraction condition. The best extraction conditions were found at extraction temperature and time of 58.93°C and 37.86 minutes, respectively.

Abstract: There is an abundance of waste contributed by most agricultural industries. Coconut industry wastes such as the (exocarp) outer layer and (mesocarp) husk can be exploited and turned into useful products such as natural dyes. In the present work, solvent extraction of natural dye from exocarp and mesocarp of Cocos nucifera using ultrasound has been studied. Methanol, ethanol and acetone with varying concentration (20%-70%) were used in the extraction process which was carried out at 30°C for 1 hour. Aqueous extraction was also performed with the same condition and acts as a control sample. The extraction of pigment from exocarp using 50% acetone produced the highest percentage of the yield of colorant (11.6%), while for mesocarp extraction, both 50% and 60% acetone yielded the highest percentage of colorant which was 9.2%. In addition, control sample (aqueous extraction of mesocarp and exocarp) showed lower percentages of the yield of colorant which was 6.4% and 6.8%, respectively. The results indicate that there was a significant improvement in the percentage of yield of natural colorant obtained due to the use of ultrasound.

Abstract: The capture of carbon dioxide (CO₂) by aqueous alkanolamine is the most cost effective technology available today. However, some problem such as amine losses, corrosion and low absorption rate arise when aqueous alkanolamines is used as an absorbent. To overcome these problems, liquid emulsion was introduced as an alternative for CO₂ removal. However, the main concern of using liquid emulsion is the stability of the emulsion. In this study, a formulation containing mixture of blended alkanolamine was used. Methyldiethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) were used as extractants and were mixed with sodium hydroxide (NaOH) solution to form the aqueous phase. Meanwhile, the organic phase consists of kerosene and Span 80. The emulsion was prepared by homogenizing both phases at speed of 10 000 rpm for five minutes. The stability of the MDEA-AMP emulsion was determined and the CO₂ absorption by the emulsion was measured. This study showed that using 8 mL MDEA and 4mL AMP, the stability of the emulsion was 74.00% and 48.05% of CO₂ was removed.