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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 320 Documents
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PENENTUAN MASA KADALUARSA LIKOPEN DARI BUAH TOMAT (Lycopersicum pyriforme) TERCAMPUR MALTODEKSTRIN DALAM KEMASAN KAPSUL Kostriana Daniel; Mappiratu Mappiratu; Ni Ketut Sumarni
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The investigation about the determination of the expired time of lycopene made from tomato (Lycopersicum pyriform) which was mixed with maltodextrin in capsule packaged has been done. The aim of the research is to determine the ratio of lycopene extract to maltodextrin for yielding lycopene with the highest purity degree and to determine the expired time. The applied ratio of lycopene to maltodextrin were 5:10, 7.5:10, 10:10, 10:7.5, 10:5 (w/w). Those samples were stored at room temperature for 10 weeks. Spektrofotometri UV-VIS was used to analyze the samples. The results showed that the highest purity degree was reached at the ratio of 10:10 (39.56%). The best expired time at the ratio of 5:10 was reached at 12.93 weeks.Keywords: Tomato, lycopene, lycopene mixed maltodextrin, purity degree, expired
EKSTRAKSI GLUKOMANAN DARI UMBI PORANG (Amorphophallus paeniifolius (Dennst.) Nicolson) Elis Setiawati; Syaiful Bahri; Abd. Rahman Razak
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

This study aims to determine the temperature and the ratio of tuber flour porang using isopropyl alcohol precipitator in producing glucomannan extract with the highest yield. The study was designed using completely randomized design (CRD), which consists of two factors: the temperature of the extraction consists of seven levels (45, 55, 65, 75, 85, 95, and 105 0C) and the ratio of tuber flour porang by precipitating isopropyl alcohol consists of 5 level (1: 7, 1:10, 1:13, 1:16, and 1:19 (w/v). each done in duplicate. parameters measured were yield characteristics glucomannan and the results showed that the extraction of the best glucomannan obtained at a temperature of 95 0C with a yield of 41.614%. the ratio of starch tuber porang best isopropyl alcohol is 1:19 (w/v) with a yield of 45.167% glucomannan. Test characteristics of glucomannan gained 6.6% moisture content, the ash content of 0.8%, and a molecular weight of 0.726 x 104 g/mol.Keywords: porang tuber flour, shaking temperature, glucomannan.
UJI AKTIVITAS ANTIBAKTERI EKSTRAK DAUN TANAMAN JOHAR (Cassia siamea Lamk.) DARI BEBERAPA TINGKAT KEPOLARAN PELARUT Fitriah Fitriah; Mappiratu Mappiratu; Prismawiryanti Prismawiryanti
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

A research about antibacterial activity test of johar plant leaf extract (Cassia siamea Lamk.) using several levels of solvent polarity has been implemented. This study aims to determine whether the antibacterial compounds in the leaves is polar, non-polar or semi-polar, and to determine the highest inhibition level of johar leaf extract on both the gram-negative bacteria (Escherichia coli and Shigella dysenteriae) and gram-positive (Staphylococcus aureus and Micrococcus luteus). The maceration method was used in this research with 3 levels of solvent polarity namely non-polar, semi-polar and polar. The bacterial activity test was done with diffusion method. The results showed that the johar leaf contains antibacterial compounds which are polar and semi-polar. The highest inhibition level was obtained at johar leaf ethanol extract for Staphylococcus aureus, Escherichia coli, Micrococcus luteu and Shigella dysentriae of 14.9, 12.9, 12, and 7.2 mm, respectively.Keywords: Antibacterial, Inhibition Level, Johar Leaf Extract
ANALISIS KADAR TOTAL METABOLIT SEKUNDER EKSTRAK ETANOL DAUN TAMOENJU (Hibiscus surattensis L.) Astrid Natalia Alasa; Syariful Anam; Jamaluddin Jamaluddin
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Tamoenju (Hibiscus surattensis L.) leaves are included in the malvaceae family which grows in the plateau and are known to have the antidiabetic activity that the standardization of the extract is needed to be conducted. The research aimed to discover the total level of secondary metabolites from ethanol extract. The extraction of Tamoenju leaves through maceration method with 96% ethanol was done to obtain the filtrate. The filtrate obtained was concentrated by using rotary evaporator at 40°C until the concentrated extract was obtained. The extract gained was then tested in a qualitative way with Alkaloid, Flavonoid, Saponin, and Tannin tests by using the suitable reagent for the test parameters. While in the quantitative test the method used was Gravimetric analysis on alkaloid and Saponin compounds, Permanganometry on Tannin compound, and UV-Visible Spectrophotometry on Flavonoid. The qualitative test results reveal that Tamoenju is positive for containing Alkaloid which was characterized by the presence of orange sediment, Flavonoid was characterized by the orange formation, Tannin was characterized by the dark blue and Saponin was characterized by the stable foam. The quantitative test results are Alkaloid by 305.181 g/g, Saponin by 371.112 g/g, Tannin by 55.417 g/g and Flavonoid by 14.999 mg/100 g.Keywords: Hibiscus surattensis L. , secondary metabolites, standardization
PRODUKSI ENZIM LIPASE DARI Aspergillus niger ISOLAT KAPANG KOPRA DENGAN MENGGUNAKAN MEDIUM KELAPA PARUT Indah Indah; Mappiratu Mappiratu; Musafira Musafira
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The investigation about the lipase enzyme production from Aspergillus niger using grated coconut as a medium has been done. The aim of the study is to determine the best incubation time, pH and water content which produced lipase enzyme with high activity. Randomized Block Design (RBD) with 2 factorial pattern (incubation time and pH of the medium) was used in this research. Each factor consists of three levels and it was done in the triple. The level of incubation time and of pH were 48, 60, 72 hours and pH 5, 6, and 7, respectively. The observed parameter was the obtained lipase enzyme activity. The result showed that the highest activity was achieved at pH 7 for 48 hours of incubation time with 45% of water content. The amount of lipase enzyme activity was 1.70 µmol/ml.minutes.Keywords: mold coconut, Aspergillus niger, lipase
KAJIAN EKSTRAK ETANOL BUNGA BOGENVIL (Bougenvillea spectabillis Willd) SEBAGAI BIOINDIKATOR ASAM BASA Nurhaeni Nurhaeni; Fitri A Bande; Rismawaty Sikanna
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Studies of ethanol extract of bougainvillea flowers (Bougenvillea spectabillis Willd) as bioindicators of the acid-base has been done. The aims to determine the content of chemical compounds contained in extracts of bougainvillea flowers and bougainvillea flower extract pH stretch. Achievement of the objectives has done through the test of ethanol extract of bougainvillea identification of compounds and the determination of the acid-base stretch of pH indicator is. The obtained results showed that bogenvil ethanol extract containing flavonoids with 401 nm absorption and provided a color change in the acid and alkaline condition the color is yellow. The appropriate acid-base titration is used as bioindicators of a strong acid titration with a strong base, weak acid with a strong base and a weak base with a strong acid.Keywords: Flowers bougainvillea, indicators, bases acid titration
PENENTUAN EFISIENSI DYE SENSITIZED SOLAR CELL (DSSC) MENGGUNAKAN EKSTRAK BUAH KAKTUS (Opuntia elatior Mill.) Christianto Pasunu; Ruslan Ruslan; Hardi Ys.
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Dye-Sensitized Solar Cells (DSSC) research by using cactus fruit extract (Opuntia elatior Mill.) has been done. The objectives of the research are to determine the highest efficiency of submersion time and Dye pH treatments of cactus fruit extract (Opuntia elatior Mill.). This research was used a Complete Random Design (CRD) method whereas the submersion time of the worked electrode on five extents of treatments are 6,12,18, 24, 30 hours and Dye pH on four extents of treatments are 1, 3, 5, and 7. The result showed that the optimum time at 12 hours with the Dye pH at 3 has resulted in the highest efficiency of 0.105. Keywords: Cactus fruit extract, Opuntia elatior Mill, efficiency, DSSC.
KAJIAN EKSTRAK ETANOL MAHKOTA BUNGA KETEPENG CINA (Cassia alata L) SEBAGAI BIOINDIKATOR ASAM BASA Khairunnisa Khairunnisa; Khairuddin Khairuddin; Dwi Juli Puspitasari
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The acid-base bioindicator is an alternative substitute for the synthetic indicator. The study about ethanol extract of Ketepeng Cina crown flowers as an acid-base bioindicator source has been done. The research about utilization of ethanol extract of Ketepeng Cina crown flower was aimed to study compound group, pH range and acid-base titration which is suitable as bioindicator. This research was performed with gradual extraction by maceration method with three solvents. The results showed that ethanol extract from Ketepeng Cina crown flowers contained flavonoid, polyphenol, alkaloid, and tannin. Extract of Ketepeng Cina crown flower was yellow in acid and orange in the base with the pH range of 7-9.Keywords: Ketepeng Cina, Bioindicator, Acid-Base, Titration.
KAJIAN KEMAMPUAN AKAR TANAMAN KANGKUNG DARAT (Ipomoea reptans Poir) DALAM MENYERAP LOGAM MERKURI PADA TANAH TERCEMAR Khairuddin Khairuddin; Rismawaty Sikanna; Sabaruddin Sabaruddin
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The Research has done on assessment ability plants of kale land root’s (Ipomoea reptans Poir) in absorbing metallic of mercury (Hg) on polluted soil. Methods of assessment done by complete randomized design (CRD) to determine the influence of plant age and concentration of the planting medium to large concentrations absorbed of mercury in plant roots. Age of planting consists of 4 harvest time, it is 2, 3, 4, and 5 weeks. The concentration of the cultivation medium is 25 ppm, 50 ppm, 75 ppm dan 100 ppm. The results of analysis variance test for the effect of cultivation age indicate the real difference (F calculation > F 5 %), where the test results of BNT 0,05 obtained in the third week is the maximum age of planting. The influence of concentration on analysis variance test and LSD analysis indicate the real difference, where F calculation > F 1%.Keywords: Absorption, Metal Mercury, Land Plants kale, Age of planting, growing media concentration.
PENGARUH PENAMBAHAN AKTIVATOR DALAM PEMBUATAN KARBON AKTIF AMPAS TAHU SEBAGAI ADSORBEN MINYAK JELANTAH Ma'rifah Ma'rifah; Jamaluddin Jamaluddin; Yonelian Yuyun; Agustinus Widodo
KOVALEN: Jurnal Riset Kimia Vol. 4 No. 1 (2018): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (612.489 KB) | DOI: 10.22487/kovalen.2018.v4.i1.9363

Abstract

Minyak goreng yang telah digunakan berulang kali akan mengalami kerusakan seperti peningkatan bilangan peroksida dan asam lemak bebas yang dapat menimbulkan bahaya bagi kesehatan. Penelitian ini memvariasikan aktivator pada proses pembuatan karbon aktif ampas tahu yaitu NaCl 10%, Na2CO3 5% dan H3PO4 1M untuk mengetahui pengaruhnya terhadap kadar asam lemak bebas dan bilangan peroksida dalam minyak jelantah. Minyak yang digunakan adalah minyak goreng kemasan yang digunakan untuk menggoreng ikan kering, ikan basah, tahu-tempe dan daging ayam. Tahapan pemurnian minyak yaitu proses despising, netralisasi dan bleaching. Pengujian mengacu pada SNI (Standar Nasional Indonesia) 7709:2012 sebagai syarat mutu minyak goreng. Hasil penelitian menunjukkan kadar asam lemak bebas tertinggi dan terendah yang diperoleh yaitu 0,1925% dan 0,1473%, sedangkan bilangan peroksida tertinggi dan terendah yaitu 9,3203 meq O2/kg dan 4,3526 meq O2/kg. Aktivator yang paling berpengaruh pada penurunan kadar asam lemak bebas dan bilangan peroksida adalah Na2CO3 dimana diperoleh kadar rata – rata asam lemak bebas 0,1473% dengan persentase penurunan sebesar 57,68% dan kadar  rata – rata penurunan bilangan peroksida yaitu 4,3526 meq O2/kg dengan persentase penurunan sebesar 59,04%. Jadi, aktivator Na2CO3 merupakan aktivator yang paling baik digunakan untuk aktivasi karbon ampas tahu sebagai adsorben minyak jelantah.Kata Kunci:    Aktivator, Karbon Aktif, Ampas Tahu, Adsorben, Minyak Jelantah. 

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