Chemical Constituent and Antioxidant Activity of Clove (Syzygium aromaticum) Bud and Leaf Essential Oils from Bali

Bali is one of clove (Syzygium aromaticum) producers in Indonesia. Clove essential oil is mainly produced from the leaves and flowers. Eugenol is the main component in the essential oil of clove. The objective of this research is to determine constituents and antioxidant activity of clove’s bud and leaf essential oils from Bali. The essential oils were isolated from clove’s bud and leaf samples by steam distillation with the yield of 12.90 and 2.63%. The constituents of the clove essential oils were analyzed by using gas chromatography-mass spectrometry (GC-MS). Thirty-six and twenty-nine constituents were identified based on GC-MS from the clove bud and leaf essential oils, respectively. Major classes of compounds are sesquiterpenes, phenyl propanoids, oxygenated sesquiterpenes, and esters. Different compositions in major constituents were found between both essential oils. Clove bud essential oil (CBEO) contained eugenol (65.29 %), trans-caryophyllene (20.06 %), and α-humulene (3.38 %). While, in clove’s leaf essential oil (CLEO), the composition was eugenol (64.47 %), trans-caryophyllene (27.19 %), and α-humulene (3.62 %). The clove essential oil and its main component show strong antioxidant activity. The antioxidant activity of CBEO, CLEO, and eugenol is 22.58, 29.19, and 17.53 μg/mL, respectively

Fatty Acid and Amino Acid Profile of Mancadu Clam (Atrina vexillum) in Waai Village

Mancadu clam (Atrina Vexillum) is a food source for Maluku coastel communities with high nutritional value and contains various bioactive components, including fatty acids and amino acids.  This study analyzed the content of fatty acids and amino acids in mancadu clams (Atrina Vexillum) in Waai village.  Fatty acid analysis was carried out through a maceration extraction process with the Shaking Incubator method and transesterification using the microwave. Amino acid analysis was carried out by hydrolysis for 12 hours. The results of the research, the fatty acids of mancadu clams contain 7 fatty acid components, consisting of 2 saturated fatty acids, namely hexadecanoic or methyl palmitate, which is the most significant component (17.61%) and heptadecanoic acid (13.43%). Unsaturated fatty acids are hydrosinnamic acid (15.01%), 5,8,11,14- eicosatetranoic acid/omega-6 fatty acid (7.2%), octadecanoic acid (6.65%), 9-Octadecanoic acid (5.1%) and 8,11-eicosadinoic acid or FUPA (4.68%). The results of amino acid analysis of mancadu clams (Atrina Vexillum) on 18 amino acids obtained 6 types of essential amino acids namely leucine, valine, isoleucine, threonine, methionine and arginine which the largest compound from acid hydrolysis (1150.94 mg/Kg). There are 7 types of nonessential amino acids: glutamic acid, alanine, serine, glycine, aspartic acid, and proline.&nbsp

Isolation of Carrageenan from Eucheuma cottonii by Variying Alkaline Solutions

The carrageenan can be isolated by combining alkaline KOH, NaOH, and Ca(OH)2 solutions. Alkaline solutions of KOH: NaOH, KOH: Ca(OH)2, and NaOH: Ca(OH)2 were combined to extract carrageenan. The amount of the solution was varied, the carrageenan groups were characterized using FTIR, and the carrageenan’s gel strength was tested. The extraction results obtained the highest yield in the combination of alkaline solutions Ca(OH)2 80%+KOH 20%, which is equal to 70.18% FTIR test results for carrageenan produced from the extraction of Eucheuma cottonii seaweed showed absorption showing the type of kappa (κ) carrageenan. The highest gel strength test results were obtained in an alkaline solution of Ca(OH)2 80%: NaOH 20%, which was 252.5 g bloom, and the lowest was made in a solution of Ca(OH)2 80%: KOH 20%, which was 21.0 g bloom

Hydrothermal Synthesis and Characterization of Sodalite from Feldspar Mesawa Minerals

The mineral feldspar is a potential raw material in zeolite synthesis because of the high content of SiO2 and Al2O3. Characterization of X-ray diffraction (XRD) and X-ray fluorescence (XRF) on Mesawa feldspar minerals showed high crystallinity and aluminosilicate composition. The synthesis process uses the hydrothermal method with various times and concentrations of NaOH. The sample was mixed with NaOH, stirred until homogeneous at 300 rpm for 1 hour, and transferred to an autoclave. The autoclave was tightly closed and heated in an oven at 170 °C for 72 hours. XRD and XRF analysis revealed that the feldspar mineral had changed to sodalite with a purity of 90.89% and 90.06%; with a yield of 80.89% and 87.36%. FTIR characteristics show a specific peak for sodalite at 422-460 cm-1 related to Si-O bond vibrations, and absorption bands at 698 and 719 cm-1 related to Al-OH vibrations. The SEM results confirmed the morphology of the sodalite resembling balls like raspberries". This research proves that the Mesawa feldspar mineral sample contains type 6 secondary building units, the same blocks as zeolite analcime and cancrinite, so it has the potential as an adsorbent for heavy metals and as a catalyst alternativ

The Sediment Profile and Heavy Metal Content of Lead (Pb), Copper (Cu), and Silver (Ag) in The Waters of Saparua Island

This study determined the distribution levels of heavy metals Pb, Cu, and Ag in sediments in the waters of Saparua Island. It characterized the sediments in the seas of Saparua Island. Parameters are physical and chemical parameters of waters, determination of total organic carbon (TOC), and digestion of sediment samples for SSA testing. The results obtained levels of copper metal contained in the sediments from 0.1583–1.9531 mg/L and <4–78 ppm. The level of lead metal contained in the sediments in the waters of Saparua Island ranges from <12–26 ppm. Metal oxides, especially metal oxides formed from Cu, were found in sediments in the waters of Saparua Island with location points P.8 and P.9, namely CuO 0.0056% and 0.0031% and in sediments in Saparua Island waters with a value of 2Ɵ in sediment samples. P.2, P.3, P.6, P.8, P.9, and P.11 have the highest intensity which is the characterization of metal oxide 2Ɵ= 27.7464°, 29.4759, 26.2979, 26.6686, 26.7007, and 24.3695 indicate the presence of CaO (calcium oxide) phases at points P.2, P.3, and P.6. the SiO2 (silica) phase which is the most abundant metal in sediment samples P.8, P.9, and P.11 based on the XRF test

Antibacterial Activity Test of Silver Nanoparticle Composites With Gandaria Seed (Bouea macrophylla G.) Bioreductor and Ouw Natural Clay Matrix (ONC)

An antibacterial activity test of silver nanoparticle composite with bioreductor of gandaria seeds (Bouea macrophylla G.) and Ouw natural clay (ONC) matrix was conducted. Silver nanoparticles (AgNPs) were synthesized by forming the colloidal silver solution by chemical reduction method using gandaria seed bioreductor. The formation of AgNPs can be known through UV-Vis absorption when there is a color change. Based on the results, the maximum wavelength of colloidal NPP is 435-444 nm. Silver nanoparticles synthesized through the preparation process were tested to determine their effectiveness as antibacterial agents against Escherichia coli and Staphylococcus aureus. The test results showed that the NPP formulation, containing an aqueous extract of gandaria seeds with the addition of polyvinyl alcohol (PVA), produced an inhibition zone of 10.6 mm against E. coli, indicating strong antibacterial activity. In contrast, the activity against S. aureus was classified as moderate, with an inhibition zone measuring 6.8 mm. For the antibacterial activity test with Ag/ONC nanocomposite samples on both test bacteria, there was no inhibition zone or antibacterial activity

Influence Of Silica Content into Nickel/Silica Electrodeposited Composite Coating for Mechanical and Corrosion Resistant Properties Enhancement: A Review

The ratio cost/efficiency of electrodeposited composite coating has boosted the development of this method in the last decades.  Thus, electrodeposited nickel with silica particles as reinforcement was successfully designed and the conditions to increase particles in the composite are better understood. Those composites' morphological, mechanical, and corrosion properties as a function of the embedded silica particles were also investigated. In this review, the last findings about nickel/silica preparations and their properties are specifically summarized. Data collected here indicate that silica particles entrapment depends on current density, particle load in the bath, particle surface modification, and hydrodynamics. The presence of silica particles in the composite led to the refinement of the nickel grain and consequently enhanced the mechanical and corrosion properties

Optimization of the Esterification Process of Crude Palm Oil (CPO) with Natural Zeolite Catalyst Using Response Surface Methodology (RSM)

Esterification is one of the important processes in the production of biodiesel. This is done to ensure that the FFA content in CPO is less than 3%. The esterification reaction can be accelerated by using natural zeolite as a catalyst. Optimization needs to be carried out to select the appropriate conditions to reach the optimal region quickly. The purposes of this research are to analyze the impact of esterification time and the natural zeolite catalyst size on the reduction of FFA levels and find the optimal parameters in the CPO esterification through RSM. Esterification is operated by maintaining the reaction temperature at 60 °C, agitation speed at 150 rpm, and using a molar ratio of methanol:CPO of 6:1. The independent variables used in the research are esterification time (90, 110, 130, 150, and 170 minutes) and natural zeolite size (20, 40, 60, 80, and 100 mesh). The optimization results using RSM indicate that the optimum points in the study are at an esterification time of 170 minutes and a natural zeolite size of 97.3909 mesh

Evaluation of Lead (Pb) Bioaccumulation Levels by sea grass (Enhalus acoroides) at Tulehu Village Port

This research aims to study the level of heavy metal Pb bioaccumulation by sea grass (Enhalus acoroides) in the waters of Tulehu Village, Central Maluku Regency, where the type of particles and Pb content in sediment, roots and leaves are important variables for studying the accumulation and translocation of Pb metal ions by sea grass. Lead (Pb) content in sediment, roots and leaves of sea grass was measured using an atomic absorption spectrophotometer. The ability to accumulate and translocate lead (Pb) in sea grass (Enhalus acoroides) is known from the BCF (bioconcentration factor) and TF (translocation factor) values. The results of the study showed that the type of sediment particle grains at point I was 2.92% gravel, 86.67% sand, 26.67% mud, the size of sediment grains at point II was 16.67% gravel, 82.94% sand, 2.35% mud, and the size of sediment grains at point III was 19.77%, 64.58% sand, 1.04% mud. The Pb metal content produced at point I ranged from 4.80 mg/kg, point II ranged from 4.85 mg/kg and point III ranged from 4.44 mg/kg. The BCF values obtained at points I, II, and III were respectively 0.55; 2.20; 2.12

Kinetic of Hexavalent Chromium (Cr(VI)) Removal by Corn Cob-Based Activated Carbon Modified with Nitric Acid

The presence of heavy metal Cr(VI) in water indicates environmental pollution. Heavy metal Cr(VI) that exceeds the standard can be harmful to health because it is toxic and carcinogenic. Activated carbon can be used as a heavy metal adsorbent. Modification of activated carbon using nitric acid can increase metal adsorption capacity. Therefore, this study aims to determine the kinetic of hexavalent chromium (Cr(VI)) removal by corn cob-based activated carbon modified with nitric acid. The modified activated carbon was characterized by Boehm titration and FTIR spectrophotometer. The adsorption capacity was identified in various parameters, involving the initial concentration of Cr(VI), pH value, contact time, and concentration of the adsorbent to obtain the optimal Cr(VI) removal efficiency value. The most optimal Cr(VI) adsorption was obtained at an activated carbon dosage of 3 g/L, pH value of 1, contact time of 140 minutes, and 100 mg/l Cr(VI) concentration. Based on adsorption kinetics data, the pseudo-second-order equation was obtained (R2 =0.994). The adsorption phenomenon followed the Langmuir isotherm model (R2 = 0.998) with an optimum adsorption capacity of 28.32 mg/g. Corn cob-activated carbon modified with nitric acid has many acidic groups that act as effective active sites for reducing Cr(VI) from water