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Ivandini Tribidasari A.
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Makara Journal of Science
Published by Universitas Indonesia
ISSN : 23391995     EISSN : 23560851     DOI : https://doi.org/10.7454/mss
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Makara Journal of Science publishes original research or theoretical papers, notes, and minireviews on new knowledge and research or research applications on current issues in basic sciences, namely: Material Sciences (including: physics, biology, and chemistry); Biochemistry, Genetics, and Molecular Biology (including: microbiology, physiology, ecology, taxonomy and evolution); and Biotechnology.
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Articles 880 Documents
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Antifreeze Proteins: Characteristics and Potential Applications Tejo, Bimo Ario; Asmawi, Azren Aida; Rahman, Mohd Basyaruddin Abdul
Makara Journal of Science Vol. 24, No. 1
Publisher : UI Scholars Hub

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Abstract

The freezing of water is usually fatal to most organisms because it causes extensive damage to cell membranes due to the formation of ice crystals. However, several structurally different classes of antifreeze proteins (AFPs) found in fish, insects, plants, and microorganisms, including bacteria, yeast, and fungi, have been found to be capable of modifying the growth of ice crystals by thermal hysteresis and ice recrystallization inhibition. This unique property could potentially be applied to medicine and the industry as it is useful when low-temperature storage is required and ice crystallization must be avoided. However, the application of AFPs today is not economically viable due to the complexity of the large proteins, the laborious procedures required, and the low yields obtained. A wide range of peptides mimicking their parent proteins were recently successfully designed and chemically synthesized. The developed approaches present new opportunities to understand the structure–function relationship of small-structured peptides with antifreeze properties. This mini-review highlights the diversity, classification, and properties of AFPs. The emerging applications of short mimetic peptides of AFPs and their potential application are also described.
Functional Properties of Purple Water Yam Flour Modified by Lactobacillus plantarum Ulyarti, Ulyarti; Yulia, Ade; Nazarudin, Nazarudin; Armando, Yunta Gombang; Erawaty, Lela
Makara Journal of Science Vol. 25, No. 1
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Abstract

Purple water yam flour modified by Lactobacillus plantarum fermentation may be used as an ingredient in flour-based functional food. The purpose of this research is to determine the effect of fermentation time on the functional properties of purple water yam flour modified using L. plantarum. This research used a randomized block design with six treatments: without fermentation (control) and 12, 24, 36, 48, and 60 h of fermentation. Results showed that lactic acid bacteria initially grow well with increasing viability over 48 h of fermentation. Growth and viability rates began to decrease as the organisms entered the declining or dying phase. Statistical analysis showed that fermentation time affects the solubility at 75 °C, chromatic color values L* and b*, and antioxidant activity of flour. Fermentation for 36 h produced the best modified purple water yam flour with an antioxidant activity of 69.82%, bulk density of 0.817 g/mL, water absorption capacity of 3.31 g/g, oil absorption capacity of 1.20 g/g, solubility of 0.45%, L* of 80.33, a* of 16.33, and b* of −5.33. The results indicate that purple water yam flour modified by L. plantarum fermentation for 36 h could be developed as a functional food ingredient.
Cr (III)-Doped Bentonite: Synthesis, Characterization and Application for Phenol Removal Purwaningrum, Widia; Vilantina, Vilantina; Rizki, Widya Twiny; Desnelli, Desnelli; Hariani, Poedji Loekitowati; Said, Muhammad
Makara Journal of Science Vol. 25, No. 2
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Abstract

Study of doping process of metal oxide Cr(III) onto bentonite for phenol removal has been done. The purpose of this study was to increase the capacity and effectiveness of bentonite adsorption.The doped bentonite was characterized using XRD, SEM-EDX and FT-IR spectrophotometer analysis. XRD characterization result showed an angle shift (2θ) characteristic at1.609°. The SEM-EDX characterization result showed that bentonite as control have a more gaps than Cr(III)-doped bentonite. Based on EDX result, the Al element decreased from 7.53% to 3.76%, Si from 19.84% to 10.23% and appeared Cr element 2.06%, The FT-IR characterization result showed no significant friction in the spectrum so it can be identified as physical adsorption. The adsorption of phenol was applied at pHpzc, which for bentonite as control was applied at pH 4 and Cr(III)- doped bentonite was applied at pH 8. The phenol adsorption rate fitted to pseudo-second-order and it was found that the equilibrium data was best followed by Freundlich isotherm model, the amount of adsorption rate constant (k) and adsorption capacity (Qe) was 0.0024 g.mg-1min-1 and 16.95 mg/g. The Enthalpy (ΔH) and entropy (ΔS) values decrease with increasing phenol concentration and the positive free energy value was indicated that the proccess was nonspontaneous because there has been an equilibrium state. Based on the adsorption result, it can be concluded that the doping method can produce better bentonite performance to adsorb phenol.
Isolation and Characterization of Ethyl Acetate Fraction from Abroma augusta L as an Anti-Inflammatory Agent Latief, Madyawati; Tarigan, Indra Lasmana; Muhaimin, Muhaimin; Amanda, Hilda; Yulianti, Nike Desvi
Makara Journal of Science Vol. 25, No. 2
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Abstract

Abroma augusta is a bush plant that lives on the edge of the river. This plant is commonly used as an anti-inflammatory drug for joints and broken bones. It contains several secondary metabolites, such as alkaloids, triterpenoids, steroids, and flavonoids, which exhibit anti-inflammatory activity. UV-visible (UV-Vis) spectrophotometry of isolate 1.3 indicated absorption at a maximum wavelength of 282 nm. The wavelength suggested that the electron transition π–π* is the absorption of UV spectra typical for triterpenoid compounds that have chromophores in the form of non-conjugated double bonds. FT-IR spectrophotometer characterization data from isolate 1.3 revealed the presence of triterpenoid compounds having carboxyl groups C-O (ester), C-(CH3)2 (gem-dimethyl), carbonyl C = O esters, and C-H (alkyl). Analyses of UV-Vis, FT-IR, GC-MS, 1H-NMR, and 13C-NMR spectra showed that the compound obtained was the triterpenoid β-amyrin. Activity test demonstrated that isolate 1.3 with a 10 mg dose showed stronger anti-inflammatory activity than the positive control of sodium diclofenac.
Effect of Chromium Metal Accumulation on the Magnesium Absorption and Chlorophyll Content in Vegetables Sulistiani, Widya Sartika; Widowati, Hening; Sari, Kartika; Sutanto, Agus
Makara Journal of Science Vol. 25, No. 1
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Abstract

This study analyzed the effect of chromium metal accumulation on magnesium absorption and chlorophyll content in vegetables. The effect of accumulation was determined by performing controlled experimental methods on planting media supplemented with chromium and by directly observing vegetables grown in chromium-polluted areas, such as mountain, rice field, street, and industrial areas. The controlled experiments were carried out by varying the chromium contamination (1 and 3 ppm) and magnesium nutrition (0.4, 0.6, and 0.8 g/L) in planting media. The controlled experiment was compared with the results of field observation in several chromium-polluted areas. The effect of the treatment was analyzed based on the chlorophyll and magnesium levels in the leaves in comparison with the chromium levels in the planting medium. The results of observation and controlled experiments showed that the accumulation of chromium in plants affected the absorption of magnesium, which also affected chlorophyll formation and thus disrupted plant growth. The high chromium level (3 ppm) and magnesium level in planting media can reduce the accumulation of chromium in kale stems and leaves by 19% and 33%, respectively, increase magnesium absorption on kale stems and leaves by 7% and 5%, respectively, and increase chlorophyll formation on kale stems and leaves by 12% and 11%, respectively. Field observation in several chromium-polluted areas showed that spinach has a better chromium accumulation tolerance than kale in terms of magnesium absorption. The type of planting media, plant species, and the presence of other metal contaminants also affect chromium accumulation, magnesium absorption, and chlorophyll level.
Effect of Harvest Age and Solvents on the Phenolic Content of Eucheuma cot-tonii Extract Purbosari, Ninik; Warsiki, Endang; Syamsu, Khaswar; Santoso, Joko
Makara Journal of Science Vol. 24, No. 3
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Abstract

Bioactive compounds in Eucheuma cottonii include phenols or polyphenols with antioxidant, antibacterial, and antiviral properties. Seaweed quality, including phenolic content, is highly determined by several factors, including the growth location, cultivation technique, and harvest age. This study aimed to determine the effect of harvest age and solvent type on the phenolic content of E. cottonii. The effects of harvest age on water content and of simplicia on the extraction process were also determined. Phenolic active ingredients were extracted at three harvest ages (35, 40, and 45 days) and using four solvents (ethanol, ethyl acetate, hexane, and water). Analysis of variance was performed to determine the effects of both factors and their interactions. The older the seaweed, the lesser the water content. The powder produced at all ages is a good simplicia for materials extraction. Results showed that high phenolic content was obtained from the E. cottonii extract at the age of 35 days with ethyl acetate as the solvent.
DFT-based Study of Electric Field Effect on the Polarizability of Three Ringed Nematic Liquid Crystal Molecules Upadhyay, Pranav; Mishra, Mirtunjai; Trivedi, Ankur; Kumar, Jitendra; Kumar, Asheesh; Kumar, Devesh
Makara Journal of Science Vol. 24, No. 4
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Abstract

Owing to its successful application to complex molecular systems, computational density functional theory (DFT) has been used to study the effect of an electric field on the molecular polarizability and HOMO–LUMO gap of 1-phenyl-4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}benzene (1) and its fluoro-, chloro-, and cyano- derivatives, namely, 1-fluoro-4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl)benzene (2), 1-chloro-4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl)benzene (3), and 4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl)benzonitrile (4). These molecules belong to the family of nematic liquid crystals with three rings: two benzene and one cyclohexane. Furthermore, two DFT approaches, namely, B3LYP and M062X, have been used to examine the results obtained. This study reveals a remarkable feature: the polarizability of these molecules follows nearly a step function when varied with respect to the electric field. The 4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl)benzonitrile (4) polarizes more than all other derivatives, whereas 1-fluoro-4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl) benzene (2) has the widest stability region of them all. With the increase in the electric field, polarizability increases in a smooth manner until a point called here the shoot-up point at which polarizability switches to a higher value and remains nearly constant as the field increases further. However, beyond a certain value of the electric field, polarizability undergoes a steep fall. It is also found that the effective length (long molecular axis) of the molecule has a direct effect on its polarizability.
Elimination of Gas and Particulate Emissions in Coal Boilers using Plasma Precipitator System Djayanti, Silvy; Suherman, Alex Lukmanto
Makara Journal of Science Vol. 25, No. 2
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Abstract

A plasma precipitator reactor is an essential part of the emission treatment. This device removes fine particles, such as dust, smoke, and various toxic gases, using the force of an induced plasma charge, minimally impeding the flow of gases through the unit. In this study, the plasma precipitator combines dust deposition-capture technology by magnetic force and emission gas removal with plasma. The reactor was successfully fabricated and tested in real-world applications of the textile industry to reduce gas and particulate emissions. Using this reactor, SO2, NO2, CO, and CO2 sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2) gases turned into more environmentally friendly forms, such as O2, with a decrease of approximately 91.3%, 91.4%, 88.3%, and 89.6% w/w, respectively. Meanwhile, the element and molecular forms, which contain sulfur, carbon, and nitrogen, were deposited as particulates in the electrode channels. Using this technology, the number of particulates decreased up to approximately 93.5% w/w. The plasma precipitator reactor does not require high electricity compared to (conventional) scrubbers that use a blower system. The results indicate that plasma precipitators can be used as an advanced technology to replace conventional gas and particulate emission removal systems from the industries.
Natural Aluminosilicate-based Y Zeolite for Catalytic Cracking of n-Hexadecane Khatrin, Irena; Saragi, Indah Revita; Ekananda, Rizki; Hanna, John Vincent; Griffith, Benyamin E; Krisnandi, Yuni Krisyuningsih
Makara Journal of Science Vol. 24, No. 2
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Abstract

Natural zeolite and kaolin are abundant in Indonesia especially in Java and Belitung islands. These materials generally contain high aluminosilicate minerals that can be used as silica and alumina sources for the formation of NaY zeolite. This research aimed to identify the modification of NaY zeolite structure using Bayat natural zeolite as alumina source and Belitung kaolin as silica source and its catalytic activity for n-hexadecane cracking. Pretreatment of materials were performed in several steps: activation, purification, fragmentation for Bayat–Klaten natural zeolite, and silica extraction for Belitung kaolin. The synthesis of NaY was performed hydrothermally using seed-assisted method with crystallization times of 24 and 48 h. The surface area analysis showed a typical surface area of microporous zeolite (i.e., a pore diameter of 1.897 nm) and surface area of 309.4 cm2/g. Meanwhile, powder X-ray diffraction characterization showed that the as-synthesized materials have the structure of NaY zeolite. The optimum crystallization time was 24 h with Si/Al ratio of 4.10. Furthermore, both synthetic and natural sourced NaY zeolites were converted into HY zeolites and employed as cracking catalyst of n-hexadecane in a fixed-bed reactor at 500 °C for 75 s. The natural sourced HY resulted in 59.80% conversion and 59.80% yield of gasoline product (C9–C12). These values were lower than the results given by synthetic HY (80%).
Improving the Surface Corrosion Resistance of AMX601 Magnesium Alloy by Acid–Alkaline Treatment Anawati, Anawati; Asoh, Hidetaka; Ono, Sachiko
Makara Journal of Science Vol. 24, No. 2
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Abstract

A drawback of acid cleaning as surface finishing of magnesium (Mg) surface is the absence of a protective oxide film on its surface. Acid–alkaline treatment is proposed to enhance the surface corrosion resistance of AMX601 Mg alloy. Acid–alkaline treatment was conducted by first dipping the alloy in HNO3–H3PO4 solution and then immersing the al-loy in NaOH solution. The potentiodynamic polarization test in 0.9% NaCl solution at 37 °C revealed a nobler corro-sion potential of −1.36 VAg/AgCl and a lower corrosion current density of 36.0 µA•cm−2 of the acid–alkaline-treated spec-imen than the acid-treated (−1.44 VAg/AgCl, 89.7 µA•cm−2) and untreated (−1.52 VAg/AgCl, 40.0 µA•cm−2) specimens. Acid treatment induced a significantly higher surface roughness (20 µm) than acid–alkaline (10 µm) and grinding (0.5 µm) treatments because of the selective dissolution of the Mg matrix and the accumulation of intermetallic precipitates. The film formed on the acid–alkaline-treated specimen was thick and free of cracks, whereas that formed on the acid-treated specimen was thin and cleaved. The formation of a protective oxide film and the enrichment of cathodic intermetallic particles on the acid–alkaline-treated specimen enhanced the corrosion resistance of the surface.

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