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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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INDONESIA
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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KAJIAN KANDUNGAN FENOLAT DAN AKTIVITAS ANTIOKSIDAN EKSTRAK ETANOL TEMPE GEMBUS DARI BERBAGAI WAKTU INKUBASI Mohammad Sidiq; Mappiratu Mappiratu; Nurhaeni Nurhaeni
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 3 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The research about study of content phenolic and antioxidant activity extract ethanol tempeh gembus of a variety of incubation has been done. This study aims to know the time of incubation and time extraction that produced levels of the total phenolic and the best antioxidant activity. Determination of total phenolic using the method of folin-ciocalteu and antioxidant activity using the method DPPH. The achievement of goals be done through the application of the treatment of the time of incubation and time extraction of level of phenolic and antioxidant activity. The influence of the time of incubation is applied five levels of 0 hours; 12 hours; 24 hours; 36 hours and 48 hours. While the influence of time extraction is 1 hours, 1.5 hours, 2 hours, 2.5 hours, and 3 hours. From the result obtained by the incubation is at the time of incubation 36 hours which resulted in levels of total phenolic of 7.75 % and the value of IC50 0f 1098.88 µg/mL. The use of time extraction is 1,5 hours that produces levels of total phenolic of 5.26 % and the value of IC50 of 1198.95 µg/mL.Keyword: tempeh gembus, total phenolic, antioxidant activity, time of incubation, time extraction
PENGGUNAAN ARANG AKTIF KULIT KACANG TANAH (Arachis hypogaea) SEBAGAI ADSORBEN DALAM PRODUKSI KAROTEN DARI FRAKSI OLEIN MINYAK SAWIT KASAR Nurhaeni Nurhaeni; Ni Ketut Sumarni; Eka Dwiyanti Tombilayuk
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 3 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Research using active charcoal leather peanut (Arachis hypogaea) as adsorbent in carotene production of crude palm oil olein fraction has conducted. This study aims to determine the ratio between active charcoal and olein that can produce the highest carotene shake time for 3 hours. Carotene analysis was conducted using UV-Vis spectrophotometry. The study design is applied is completely randomized design (CRD), with 5 variations adsorbent ratio is 1: 5; 1,5: 5; 2: 5; 2,5: 5; 3: 5 w/v and each stage is repeated twice. Results of this research showed that the ratio of peanut skin adsorbent 2: 5 w/v have the best adsorption weighing carotene obtained at 0,72 mg and percent absorption by the adsorbent reaches 97,3%.Keywords: Peanut Leather, Adsorbents, UV-Vis spectrophotometry, Carotene.
KAJIAN AKTIVITAS ANTIOKSIDAN EKSTRAK DAUN TEMBELEKAN (Lantana camara L) BERDASARKAN TINGKAT KEPOLARAN PELARUT Oktavian Mangela; Ahmad Ridhay; Musafira Musafira
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 3 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The investigation about the antioxidant activity of tembelekan (Lantana camara L) leaf extract based on level polar solvent . Has been done the aim of this study was to determine the IC50 value and to know the content of antioxidant compounds from tembelekan leaf extract based on the level of polar solvent the extraction of tembelekan leaf was done with maceration method . The result showed that ethyl acetate extract of tembelekan leaf has the highest antioxidant activity with IC50 value was 71,70 ppm. Keywords: Tembelekan ( Lantana Camara L ) , IC50 , Antioxidant , DPPH
PEMANFAATAN GETAH BIDURI DALAM PRODUKSI ALBUMIN IKAN GABUS (Ophiocephalus striatus) Ita Mustrini; Mappiratu Mappiratu; Nurakhirawati Nurakhirawati
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 3 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The Research about utilization of sap Biduri in the production of albumin fish cork (Ophiocephalus striatus). Has been done This research  purposes to determine the ratio of sap Biduri to extract cork fish that produce the protein albumin with the highest yield and optimum heating time which produces the highest yield of the protein albumin. The study used a completely randomized design (CRD), which consists of the influence of the ratio of sap Biduri to extract protein and the effect of heating time Biduri to extract latex mixture. Each treatment is done twice to obtain 22 units of the experiment. The highest protein yield was obtained at a ratio of sap Biduri 3,0 : 30 and the heating time of 60 minutes at 53,43 %. The purity of the highest degree obtained at the optimum 50 minutes warm up period of 35.50 %.Keywords : Fish Cork, Biduri Protease enzyme, Protein yield of albumin, Albumin purity degree
PRODUKSI MALTODEKSTRIN DARI TEPUNG SAGU MENGGUNAKAN ENZIM Α-AMILASE Sunari Sunari; Syaiful Bahri; Hardi Ys.
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 3 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The title of  this research is “ the production of maltodextrin of sagoo flour using α-amylase”. The objective of this research is to find out the amount of sagoo flour, enzym and time reaction the produced maltodextrin with the highest dextrosa equivalent. To find the highest dextrosa equivalent, the treatment was vary the weight of sagoo flour, the amount of enzym and time. The variation of sagoo flour weight was 6, 8, 10, 12 and 14 gram. The variation of enzym is 0.1, 0.11, 0.12, 0.13, and 0.14 mL. The variation of time was 70, 80, 90, 120, 150, 180 and 210 minutes. The results of this research showed the best sagoo flour is 8 gr with de amount is 11,835, and the best omount of enzym is 0,14 mL with de amount 21.71, the best time reaction is 120 minutes with de amount is 17.625Keywords: sagoo flour, enzym α-amylase, maltodextrin
SINTESIS DAN KAREKTERISASI SENYAWA KIRAL HASIL REAKSI ANTARA METILEUGENOL KASAR DENGAN ASAM ASETAT Muh. Hajir S. Lasapo; Erwin Abdul Rahim; Ruslan Ruslan; Indriani Indriani
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 3 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The research about synthesis and characterization of chiral compounds from the rough methyleugenol with acetic acid as the catalyst has been done. The goal is to determine the  content of 1-(3,4-dimetoksifenil)-2-propanil acetate compound which is produced in the reaction process of metileugenol with acetic acid and to characterizased the chemical compound of the product. The results showed that the content of 1-(3,4-dimetoksifenil)-2-propanil acetate compound that has been obtained was  45.87% with a molecular weight of 238.Keywords : Methyleugenol, Chiral, FT-IR, GC-MS
PEMANFAATAN SANTAN INSTAN KADALUARSA UNTUK PRODUKSI MINYAK SECARA FERMENTASI Megmerio Soro; Syaiful Bahri; Erwin Abdul Rahim
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 3 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

This research use the expired instant coconut milk for 2 months. The goal is to find out whether the coconut milk can be used to produce oil. The method does is with variation of the total  number of laru 0,5 mL oil; 0,75 mL; 1 mL; 1,25 mL; and 1,50 mL by volume per volume (v/v). the fermentation time and 18 hours, 24 hours, 30 hours, and 36 minutes. Results of the study that the amount of oil the oil laru yield the highest oil is 1,50 mL with 28% yield and fermentation time of 30 hours, while the lowest was at the time of fermentation 18 hours i.e. 15%.Keywords: instant coconut milk, expired, coconut oil, yeast, oil, quality and  yield
HIDROLISIS SELULOSA DARI SEKAM PADI (Oryza sativa) MENJADI GLUKOSA DENGAN KATALIS ARANG TERSULFONASI Adeks Pramana; Abdul Rahman Razak; Prismawiryanti Prismawiryanti
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 3 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Cellulose hydrolysis from rice husk (Oryza sativa) into glucose with sulfonated charcoal catalyst was conducted. The aim of this research was to determine sulfuric acid concentration and contact time on the sulfonation process of charcoal which would produce the highest glucose rendement from cellulose hydrolysis of rice husk. Sulfuric acid concentrations in this experiment were 8, 10, and 12 N with variation of contact time of 4, 6, 8, 10 and 12 hours respectively.  Rice husk was delignified with NaOH 10% to produce cellulose which was hydrolyzed by sulfonated charcoal catalyst. Hydrolysis reaction with the ratio cellulose/aquadest 1:25 (w/v) was conducted in autoclave with temperature 130 oC for 3 hours. The result showed that 8 N concentration of sulfuric acid and 12 hours of contact time produced the highest glucose rendement 17,9%. Keywords : rice husks, cellulose, glucose, sulfonated charcoal
PRODUKSI DAN UJI AKTIVITAS ENZIM KITINASE DARI ISOLAT BAKTERI TERMOFILIK B1211 ASAL AIR PANAS BORA Jaya Hardi; Jusman Jusman; Abdul Rahman Razak; Silva Silva
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 3 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

This research aims to production of chitinase from thermophylic bacteria that living in Bora hot spring  and to determine of chitinase extracts activity. The research was began with rejuvenated of B1211 bacteria isolates on MSM agar media.  The B1211 isolates was used to production of chitinase extracts on MSM broth media with chitin colloidal concentration of 0.25%, 0.5%, 1%, 2%, 4% and incubation temperature of 30oC (rt), 37oC, 50oC, and 60oC for 3 days. The chitinase activity were analyzed based on N-acetyl-D-glucosamine standard. The results was showed that B1211 bacteria isolates is potential isolate for production chitinase. The highest activity of chitinase from B1211 bacteria isolates of 0.75 U/mL for chitin colloidals concentration of 1% and temperature of 60oC.Keywords : Bora, hot spring, bacteria, thermophylic, B1211 isolates, chitinase.
ANALISIS PENETAPAN KADAR NIPAGIN DALAM SEDIAAN BODY LOTION TIE (TANPA IZIN EDAR) YANG BEREDAR DI PASAR TRADISIONAL KOTA PALU Vini Mandasari; Syariful Anam; Yonelian Yuyun
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 3 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

This study aims to determine the levels of nipagin as preservative in body lotions which have no marketing authorization (MA). Each sample was taken from 4 traditional markets located in Palu City. The assay of nipagin in the body lotions was done by using ultraviolet (UV) at wavelength of 257 nm. From 8 different samples, 5 of them contain nipagin of which levels are as follows: A1 = 0.232%; A2 = 0.229%; B1 = 0.124%; B2 = 0.120%; C1 = 0.120%; C2 = 0.117%; and D1 = 0.267%; D2 = 0.273%; and F1 = 0.213%; and F2 = 0.215%. Based on the results obtained, those body lotions that have no marketing authorization meet the requirement of nipagin’s preservative levels according to Analitical Method of National Center for Drug and Food Testing, in which the allowed levels of nipagin for body lotion is 0.4%.Keywords: Body Lotion, Nipagin, Ultraviolet Spectrophotometer.

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