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Jaya Hardi
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Program Studi Kimia Fakultas MIPA, Uniiversitas Tadulako Jl. Soekarno-Hatta Km. 9, Tondo Palu, 94117
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KOVALEN: Jurnal Riset Kimia
Published by Universitas Tadulako
ISSN : -     EISSN : 24775398     DOI : https://doi.org/10.22487/kovalen
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry
KOVALEN: Jurnal Riset Kimia is a peer-reviewed journal of chemistry published by the Tadulako University, Indonesia. This journal concern with publishing the original research articles, review articles, and the current issues related to chemistry. Publishing frequency 3 issues per year, in April, August, and December.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 13 Documents
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Search results for , issue "Vol. 6 No. 3 (2020): Edisi Desember" : 13 Documents clear
Mikroenkapsulasi Ekstrak Kulit Buah Naga Super Merah (Hylocereus costaricensis) pada Berbagai Massa Maltodekstrin dan Aplikasinya Sebagai Antioksidan: Microencapsulation of Super Red Dragon Fruit (Hylocereus costaricensis) in Various of Maltodextrin Mass and its Application as an Antioxidant Sucianti; Nurhaeni; Jaya Hardi
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.9889

Abstract

Red super dragon fruit peel (Hylocereus costaricensis) extract has capability to scavenge DPPH and the activity could be maintained by using maltodextrin as coating. The aims of the research are to determine ratio of red super dragon fruit peel ethanol extract toward maltodextrin producing microcapsule with the highest coating efficiency and DPPH scavenging content by microcapsule of red super dragon fruit peel extract. Microencapsulation was carried out using freeze drying technique. Comparison of red super dragon fruit peel extract and maltodextrin were 1: 8, 1: 10, 1: 12, and 1:14 (w / w). The results show that the highest efficiency ratio of coating extract of red super dragon fruit peel with maltodextrin was 1: 8 with percentage of 90,77%. Level of DPPH scavenging content of red super dragon fruit peel extract microcapsule with ratio of 1:8 on 5 minutes and 60 minutes each is 27.36% and 46.62%. Keywords: Hylocereus costaricensis, freeze drying, maltodextrin, microencapsulation
Sintesis Metil Ester Asam Lemak dari Biji Alpukat (Parsea americana Mill) Menggunakan Polimer Penyangga Katalis Berbahan Dasar Eugenol: Synthesis of Fatty Acid Methyl Ester from Avocado Seeds (Parsea americana Mill) using Polymer Support Catalyst Based on Eugenol Sumarni; Erwin Abdul Rahim; Ni Ketut Sumarni; Ruslan; Hardi Ys.; Moh. Mirzan
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.13053

Abstract

Research on the manufacture of methyl esters from avocado seeds (Parsea americana Mill) with eugenol-based catalysts has been conducted. The aim is to determine the catalyst concentration used to produce methyl esters with the highest rendement and determine the composition of fatty acid methyl ester in avocado seeds. This study was used variations in concentrations of 0.25%, 1%, 1.75%, 2.25%, and 3%. The results of this study showed that the best concentration is 2.25% with the calculation of the results of 24.8% methyl esters in avocado seeds, namely lignoceric and octadecenoic acid methyl ester. Keywords: Avocado seeds, fatty acid methyl esters
Aktivitas Antioksidan Akar Bawang Merah Lokal Palu (Allium cepa Var Aggergatum L.) dengan Berbagai Kepolaran Pelarut: Antioxidant Activity of Local Shallot Roots (Allium cepa Var Aggregatum L.) in Palu City with Various Solvent Nur Faidah; Nurhaeni; Ahmad Ridhay; Jusman; Abd. Rahman Razak; Syaiful Bahri
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.13662

Abstract

Research on the antioxidant activity of the local onion roots of Palu (Allium cepa Var Aggregatum L.) with various polarity solvents has been carried out. This study aims to determine the potential of Palu local shallot root extract as an antioxidant and determine the IC50 value of the Palu local shallot root antioxidant activity. The method applied in this research is maceration using n-hexane, ethyl acetate, and ethanol. The extracts from each solvent were tested for their antioxidant activity by the DPPH method. The results of the study showed that the IC50 value in n-hexane extract, ethyl acetate extract, and ethanol extract were 579.98 ppm, 518.28 ppm 315.83 ppm and as a comparison used ascorbic acid obtained IC50 of 53.69 ppm. Based on the results obtained, the best antioxidant activity is in polar solvents (ethanol extract) compared to other solvents. Keywords: Antioxidants, roots, Palu local shallots, Allium cepa Var Aggregatum L.
Ekstraksi dan Uji Stabilitas Zat Warna Alami dari Bayam Merah (Alternanthera amoena Voss): Extraction and Stabilization of Natural Dyes from Red Spinach (Alternanthera amoena Voss) Khairuddin; Joy Noldy Baciang; Indriani; Nov Irmawati Inda
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.13670

Abstract

Research on the extraction and stability test of natural dye from red spinach (Alternanthera amoena Voss) has been carried out. This study aims to determine the effect of pH and length of sun exposure on the stability of the dye from red spinach. Extraction using the maceration method with ethanol solvent and measurement using a UV-Vis spectrophotometer. Stability testing is carried out at pH 2-5 and sun exposure for 1-4 hours using a dark and light container. The results obtained, at pH 2 and pH 3, anthocyanins were more stable, compared to pH 4 and 5 which had greater color degradation. In exposure to sunlight, dark containers with a degradation percentage of 31.70% were better than clear containers with a percentage of 48.78%. Keywords: Anthocyanin, red spinach, natural dyes stability.
Pengaruh Variasi Konsentrasi NaOH Terhadap Nilai Derajat Deasetilasi Kitosan dari Limbah Cangkang Kerang Hijau (Perna viridis L): The Effect of NaOH Concentration on The Value of The Deacetylation Degree of Chitosan from Green Mussels Shell Waste (Perna viridis L) Winda Trisna Wulandari; Nurzaman; Anindita Tri Kusuma Pratita; Keni Idacahyati
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15277

Abstract

Chitin which is the result of processing from green conch shell waste can be transformed into chitosan through a deacetylation process using variations in the concentration of NaOH. This study aims to determine the optimum conditions of variations in base concentration to the value of the degree of deacetylation of chitosan. The types of bases used are NaOH with the concentration variations of 50%, 55%, and 60%. Chitosan obtained was calculated the yield and characterized using FTIR. The results showed the optimum condition of the value of chitosan deacetylation degree was achieved by using 60% NaOH which produced the highest deacetylation degree value of 76.5%. Keywords: Green mussels shell, chitin, chitosan, deacetylation
Pengaruh Konsentrasi Surfaktan Non-Ionik Terhadap Viskositas Perekat Polivinil Asetat Berbasis Air: Effect of Non-Ionic Surfactant on Water-Based Adhesive Viscosity Rony Pasonang Sihombing; Robby Sudarman; Agustinus Ngatin
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15278

Abstract

Substrate combining could be done by using adhesive. In Indonesia, especially industrial field, solvent base adhesives were still being developed. This kind of adhesive was not environmental friendly and not safe handling. Therefore, Polyvinyl Acetate (PVAc) water-based adhesive was prepared as an outcome of this research as one of solution to overcome the problem above. Effect of surfactant concentration on the viscosity was aimed at this research. Semi continuous polymerization with stirring motor rates on 50 – 500 rpm was used (optional). Pressure of 1 atm, 750C temperature, 5 – 6 hours reaction time for each was used as polymerization operation in this research. Vinyl Acetate Monomer (VAM), partial hydrolysis Polyvinyl Alcohol (PVOH), water, Ammonium Persulfate (APS) were prepared as raw material. NP-10 and NP-06 were non-ionic surfactants which each concentration was varied in this research. Water-based adhesive with NP-06 concentration variation resulting in viscosity from 98 m.Pa for 0.17 %wt concentration to 213 m.Pa for 0.68 %wt concentration. While NP-10 concentration variation resulting viscosity from 143 m.Pa for 0.17 %wt to 321 m.Pa for 0.68 %wt concentration. Therefore, adhesive with NP-10 surfactant concentration variable has a higher viscosity rate than NP-06 ones. Keywords: Water-based adhesive, non-ionic surfactant, adhesive viscosity
Analisis Kadar Vitamin C Bawang Putih dan Hitam dengan Metode Spektrofotometri UV-Vis: Analysis of Vitamin C Levels of Garlic and Black Garlic by UV-Vis Spectrophotometric Method Magfira Jurwita; M. Nasir; Abdul Gani Haji
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15289

Abstract

An analysis of vitamin C levels of garlic and black garlic was done by UV-Vis spectrophotometric method. Garlic and black garlic contain a variety of nutrients and vitamins. Single and plural garlic is widely used as a medicine, besides garlic is currently also popular with garlic which is processed at temperatures between 60-80̊C with an environmental humidity of around 70-90% for 10-40 days. One of the vitamins contained in garlic includes vitamin C which acts as an antioxidant and is effective in dealing with free radicals. Vitamin C analysis was performed by the spectrophotometric method on the maximum wavelength is 250 nm with an absorbance value of 3.994. Results of analysis of vitamin C levels single garlic by 0.28% content of plural garlic by 0.27%. Vitamin C levels of single black garlic 0.29% (10 days), 0.31% (20 days), and 0.32% (30 days), plural black garlic Vitamin C levels 0.28% (10 days), 0.29% (20 days) and 0.31% (30 days).Based on ANOVA test results obtained there are differences in levels of vitamin C in single black garlic over several variations of time (days)and there are differences in levels of vitamin C in plural black garlic over several variations of time (days) because of Fcount ≥ Ftable.The coefficient of variation (KV) value is needed to test the level of accuracy of the analysis results. KV value in single garlic is 0.68% and plural garlic is 1.24%. KV value of single black garlic 0.3% (10 days), 0.25% (20 days), and 0.7% (30 days), KV of black garlic 0.55% (10 days), 0.61% (20 days), and 0.43% (30 days). Keywords: Single garlic, garlic plural, black garlic, fermentation, vitamin C levels
Konversi Karat Besi Menjadi Besi (III) Sulfat dan Pemanfaatannya Sebagai Adsorpsi Pewarna Tekstil: Iron Rust to Iron (III) Sulphate Conversion and the Utilization as Textile Dye Adsoption Ngatin Agustinus; Fatimah; Widya Fitria Nur Fauziah; Rony Pasonang Sihombing
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15308

Abstract

Iron rust was an iron oxide compound that was less attractive, dirty, brown in color, and could pollute the environment, causing water to turn brown. To minimize iron contamination, conversion was carried out into iron (III) sulfate which was useful as an adsorbent for textile dyes. The purpose of this study was to determine the effect of sulfuric acid concentration and volume of H2O2 10% used to convert iron rust into optimal iron (III) sulfate compounds. The method used was a laboratory experiment on a batch scale and the hydrate content in iron (III) sulfate was carried out by the gravimetric method and its ability as an adsorbent was carried out based on the adsorption of dyes using the spectrophotometric method. The results showed that a reactor filled with 3 grams of iron rust powder and 100 mL of sulfuric acid was stirred at 425 rpm at 80 0C for 30 minutes, added 15 ml 10% H2O2 followed by stirring and heating until the solution was saturated, cooled to form crystals. The crystalline yield in these conditions was the increase in sulfuric acid concentration which resulted in low process efficiency, namely 30.34% at 50% sulfuric acid concentration and 15 mL 10% H2O2. The addition of 10% H2O2 solution to 50 mL of 20% sulfuric acid solution and 3.0 grams of a carat as much as 5 mL-10 mL 10% H2O2 produced iron (III) sulfate with 26.53% process efficiency. Iron (III) sulfate is a white, light gray crystal with the chemical formula Fe2 (SO4)3.5 H2O which was a rhombic shaped crystal. and able to absorb the dye which showed that 1.0 g of iron (III) sulfate was able to absorb the highest amount of red dye in a volume of 100 mL of textile dye solution. Keywords: Iron rust, synthesis, iron (III), sulfuric acid, textile dyes
Karakterisasi Simplisia dan Uji Aktivitas Antioksidan Ekstrak dan Fraksi Daun Pidada Merah (Sonneratia caseolaris L): Characterization and Evaluation of Antioxidant Activity of Red Pidada Leaves (Sonneratia caseolaris L) Eka Siswanto Syamsul; Supomo; Siti Jubaidah
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15319

Abstract

Research on red Pidada leaves (Sonneratia caseolaris L.) which is a mangrove plant with antioxidant potential has been carried out. This study aims to determine the simplicia characterization and activity of red Pidada leaf extracts and fractions as antioxidants. The results of the simplicia characterization were: water-soluble extract content of 11%, ethanol-soluble extract content of 16%, water content of 9%, ash content of 8.17%, and acid insoluble ash content of 0.48%. The antioxidant activity test was carried out using the DPPH (1,1-diphenyl-2-picrylhydrazyl) method. The antioxidant activity was determined by the IC50 (Inhibition Concentration) value. The results showed that the ethanol extract had an IC50 value of 24.22 ppm (very strong), n-hexane fraction 88.18 ppm (strong), ethyl acetate fraction 15.39 ppm (very strong), and ethanol fraction 38.41 ppm (very strong) Keywords: Sonneratia caseolaris L., antioxidants, DPPH, IC50
Uji Potensi Nefropati Diabetes Daun Sirih Merah (Piper croatum Ruiz & Pav) pada Tikus Putih Jantan (Rattus norvegicus): Potential Test of Diabetes Nefropative of Red Betel Leaf (Piper croatum Ruiz & Pav) on Male White Rats (Rattus norvegicus) Joni Tandi; Rizaldy Lalu; Magfirah; Yunlis Silintowe Kenta; Ronaldy Nobertson
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15323

Abstract

This study aims to determine the type of secondary metabolite compounds in red betel leaf ethanol extract, the potential of red betel leaf ethanol extract on blood glucose, creatinine, and urea levels of male white rats induced by streptozotocin. This study used 30 white male rats which were divided into 6 groups: normal control, negative control, positive control, the dose of 150, 250, and 350 mg/kg BW. The showed that results ethanol extract of red betel leaves contained alkaloids, flavonoids, phenols, saponins, and tannins. Ethanol extract of red betel leaf at a dose of 150 mg /kg BW is an effective dose in reducing levels glucose blood with an average value of decreased blood glucose levels of 238.25 mg/dL, and has an effect on creatinine and ureum, with an average dose of 350 mg/kg BW with a mean creatinine level of 0.64 mg/dL and mean ureum of 39.68 mg/dL. Keywords: Creatinine, ureum, red betel leaf, streptozotocin

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