Materials Science Forum Vol. 981

Abstract: The current research studied about the utilization of modified coal fly ash (CFA) as catalyst for biodiesel production from coconut oil. Coal Fly ash (CFA) is a solid waste that is abundantly available in the coal-based power plant. Coal Fly Ash is a type of material that has high content of oxide minerals, e.g. silicates and silicate alumina. With proper physical/chemical treatment, the coal fly ash can be converted into a heterogeneous catalyst. In this work, the coal fly ash was modified with HCl and Ca(NO₃)₂·4H₂O and used as catalyst for biodiesel production from coconut oil. This paper will focus only on the characteristics of the prepared modified CFA-based catalyst. The modified CFA-based catalyst was characterized for its crystallinity using X-Ray Diffraction (XRD), determined its surface area and pore size distribution using Surface Area Analyzer, and its functional groups by Fourier Transform – Infra Red (FT-IR). The specific surface area of the catalyst (modified CFA) decreased from 28.08 m²/g to 17.54 m²/g after impregnation process of calcium oxide in the raw coal fly ash. This decrease was also accompanied by a decrease in the average pore network from 32.59 Å to 20.31 Å. Additionally, based on the XRD pattern shown, the raw CFA is composed of mostly quartz (SiO₂) and mullite (3Al₂O₃.2SiO₂) minerals, and a small portion of hematite.

Abstract: Four models were developed to assess the development of non-enzymatic browning and antioxidant activity in mixtures of sea cucumber derived gelatin (control), gelatin-glucose, gelatin-fructose and gelatin-glucosamine. All gelatin-sugar models were prepared in mixtures consisted of 5% w/v gelatin and 1.25% w/v sugar and compared against a control (5% w/v gelatin). The mixtures were incubated at 37 °C and 70 °C respectively for up to 24 h. The progress of non-enzymatic browning was monitored via changes in absorption at 280 nm, 320 nm and 420 nm. The gelatin-glucosamine model showed greater development in early Maillard reaction products (280 nm) and pre-melanoidins (320 nm) when incubated at 70 °C after 16 h of incubation. Meanwhile lower incubation temperature (37 °C) promoted browning development (420 nm) in all the models. The gelatin-glucosamine mixture incubated at 70 °C showed high potency in antioxidant activity (p<0.05), this is in accordance to the greater reactivity of glucosamine in the formation of Maillard reaction products at the early and intermediate stages. The results suggested the gelatin-glucosamine model can be further optimized to achieve high potency in antioxidant activity and a desired browning intensity to cater specific applications such as in food and biomaterials.

Abstract: The Government of Indonesia is trying to reduce crude oil and oil fuel imports in order to minimize the balance of trade deficit through increasing utilization of biofuel. One of the options is to increase palm oil production to be processed into biofuel which can be utilized domestically. Crude palm oil (CPO) production is expected to continue to increase and is prospective to be used as a feedstock for making green gasoline and green diesel. Green gasoline production through catalytic cracking process while producing green diesel through hydrotreating process. The development of green fuel (green gasoline and green diesel) is technically possible and prospective. Production of green gasoline and green diesel by 2020 will be able to reduce import of gasoline and diesel oil by 8.9% and 31.8% respectively. Green fuel is only effective in reducing the import value of gasoline and diesel in the period 2025-2040 because there are constraints on the availability of CPO. Production of green diesel and green gasoline can reduce fuel imports so that it indirectly increases energy security. The development of the green diesel and green gasoline industry requires a clear and gradual grand strategy from the government so that feedstock needs will not interfere with food needs.

Abstract: Fruit bromelain is a proteolytic enzyme harbouring cysteine catalytic residue found abundantly in pineapple fruit. The expression of cysteine proteases is usually regulated during fruit ripening. In the present study, we aimed to study the expression and proteolytic activity level of fruit bromelain during the ripening stage of A. comosus cultivar MD 2. The gene expression of fruit bromelain was investigated via relative gene expression analysis using qPCR while the proteolytic activity of fruit bromelain was analysed via enzymatic assay using casein as a substrate. The qPCR analysis revealed that the expression of fruit bromelain was down-regulated 10-fold in ripe pineapple fruits. Besides that, the unripe pineapple fruits [1.9101 ± 0.0831 U/mL] had a higher proteolytic activity than the ripe MD 2 pineapple fruits [1.1333 ± 0.0896 U/mL]. This result showed that the function of fruit bromelain may be related to the protection of young pineapple fruits during the fruit development stage.

Abstract: Nowadays due to the depletion of non-renewable energy resources, production of green material from domestic wastes has played an important role. The waste of banana peel impregnated with calcium oxide (CaO) from eggshell had successfully been used as a low-cost catalyst to transesterify soybean oil to produce methyl ester. The catalytic actions from potassium and calcium oxide content in calcined banana peel (700 °C) and eggshell (900 °C) discover through FT-IR, XRD, and SEM. Production of methyl ester obtained at 82.29 wt. % with the optimal condition of 7 wt. % of catalyst amount, methanol/oil mass ratio, 9:1; and the reaction temperature, 65 °C within 2 h reaction time.

Abstract: Cassava peel and used newspaper are example of daily solid wastes that continue to increase in Indonesia from year to year. Most of people in Indonesia have not utilized cassava (Manihot Esculenta L.) peel and used newspaper properly, hence they only become untreated wastes. Cassava peel highly contains carbohydrate and starch which is about 44 - 59%, while newsprint contains quite a lot of cellulose which is 61%, so that both wastes have the potential to make bio-ethanol as a one of potential renewable energy source. The focus of this study is to produce bio-ethanol from these two waste materials. There were several stages to produce bio-ethanol, which are hydrolysis with 0.1 N hydrochloric acid (HCl), and fermentation with yeast (Saccharomyces Cerevisiae), and separation of the bio-ethanol by distillation. The content of bio-ethanol produced was analyzed by Gas Chromatography (GC). The bio-ethanol was produced under different variables, which are: amount of yeast (8 g and 10 g), fermentation time (3, 7, and 10 days), and ratio of volume of solution (mL) cassava peel waste : used newspaper (i.e. 80:20; 60:40; 50:50; 40:60). The GC analysis results showed that the bio-ethanol contents were approximately 0%, 6.194%, 8.421% and 8.887% for ratio volume of solution (mL) cassava peel waste : used newspaper of 80:20; 60:40; 50:50; 40:60, respectively. Whereas, the bio-ethanol contents for 3, 7, and 10 days of fermentation time were 6.690%, 8.765%, and 9.472%, respectively. In this study, the highest bio-ethanol content produced (i.e. 9.472%) was in the following variables: amount of yeast 10 g, 10 days fermentation time, ratio volume of solution (mL) cassava peel waste : used newspaper of 50:50.

Abstract: Ananas comosus plants produced enzyme called bromelain which acts as an anti-browning agent with the enzymatic inhibition to inhibit fruits browning thus prolong the life span of fruits. The properties are also discovered in aloe vera plant extract which act as an edible coating that can provide nutrients whilst improving anti-browning agent reaction. In the present study, we aimed to elucidate the inhibitory properties of bromelain and aloe vera extract to the enzymatic browning reaction of fresh pear slices. Our result showed that the combination of bromelain and aloe vera extract are able to reduce browning reaction of pear slices by inhibiting the polyphenol oxidase (PPO) reactions. Hence, this study suggest that bromelain and aloe vera work well as anti-browning agents and suitable to be used as natural food additives that can provide nutrients while maintaining food quality.

Abstract: Nanofiber has been widely used in various applications including agriculture, biomedical, pharmaceutical, and many other industries. In this study, nanofiber chitosan/PVA is utilized as an adsorbent for gold recovery due to its superior properties to adsorb metal ions from a solution. Adsorption isotherm was analyzed using the Langmuir and the Freundlich models. These models were used to evaluate the experimental data. In order to determine the more efficient models of gold recovery by using nanofiber chitosan/PVA, regression analysis methods were used to evaluate the data. Based on the result, we found that the Freundlich model was the best model for this study with parameters. This result also indicates that the biosorption process of gold in the nanofiber chitosan/PVA is a multilayer in heterogeneous surface and physical process.

Abstract: Acetosolv technique is considered as one of the best alternative way to extract technical lignin from biomass as it has high efficiency and environmentally friendly. In this study, microwave-assisted acetosolv technique were used to extract lignin from oil palm empty fruit bunch (OPEFB) in the presence of 3% sulfuric acid catalyst reacted at various temperature. The yield of the extracted acetosolv lignin were calculated using modified Technical Association of the Pulp and Paper Industry biomass composition analysis (TAPPI) method. The result showed that, as the temperature increased from 90 to 110 °C, the yield of lignin extracted also increase from 43.07 to 76.98%. The presence of guaiacyl and p-coumarate indicates the presence of active sites at C-3 and C-5 of aromatic ring for polymerization reactions. Scanning Electron Microscopy images showed that removal of lignin are intensified as the microwave-assisted acetosolv temperature increased.

Abstract: The discovery of potent anti-inflammatory agents through inhibition of prostaglandin E₂ (PGE₂) via microsomal prostaglandin E₂ synthase-1 (mPGES-1) blocking has been proven to be an important game changer in pharmaceutical industry in recent years. In this study, new chalcone derivative has been successfully synthesized via Claisen-Schmidt condensation reaction. The compound was then docked into mPGES-1 active site to predict anti-inflammatory properties through ligand-enzyme interaction investigation. The data collected from in silico molecular docking simulation and pharmacophore modeling studies provide important insight on the molecular conformation and further shed light towards structural modification of the future novel mPGES-1 inhibitor.