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All Journal Reaktor International Journal of Science and Engineering (IJSE) JURNAL TEKNOLOGI KIMIA DAN INDUSTRI Jurnal Aplikasi Teknologi Pangan Indonesian Journal of Chemistry ASEAN Journal of Chemical Engineering Jurnal Pasopati : Pengabdian Masyarakat dan Inovasi Pengembangan Teknologi International Journal of Renewable Energy Development Bulletin of Chemical Reaction Engineering & Catalysis
Aji Prasetyaningrum
Chemical Engineering Department, Faculty Of Engineering, Diponegoro University, Jl. Prof. Sudarto, Tembalang-Semarang, 50275, Telp/fax: (024)7460058/(024)76480675
Aerospace Engineering Agriculture, Biological Sciences & Forestry Automotive Engineering Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Energy Engineering Environmental Science Immunology & microbiology Industrial & Manufacturing Engineering Materials Science & Nanotechnology Other

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KINETIKA REAKSI DEPOLIMERISASI KARAGINAN PADA SUHU DAN pH OPTIMUM DENGAN KATALISATOR ASAM SULFAT Inggrid K. Wardhani; Samir Badres; Aji Prasetyaningrum
JURNAL TEKNOLOGI KIMIA DAN INDUSTRI Volume 2, Nomor 4, Tahun 2013
Publisher : Jurusan Teknik Kimia, Fakultas Teknik, Universitas Diponegoro,

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (201.571 KB)

Abstract

Karaginan merupakan polisakarida alami yang dihasilkan dari proses ekstraksi alga merah kelas Rhodophyceae  dan merupakan polimer dari unit α-L- dan/atau α-D- atau β-D-galaktopyranosil.. Karaginan sangat bermanfaat dalam bidang biomedis karenamemiliki sifat  elektronegatif yang kuat. Kerapatan muatanantara estersulfat yang ada memungkinkan terjadinya interaksi elektrostatikdengan protein secara spesifik, sehingga menyebabkan munculnya fungsi aktivitas biologi senyawa tersebut.Penggunaan karaginan  dalam aplikasi biomedis  sering dibatasi oleh ukuran berat molekul dan viskositasnya yang tinggi. Dengan merubah menjadi (Low Molecular Weight Fractions (LMWFs), karaginan memiliki rantai yang  lebih pendek sehingga  dapatmasuk ke dalam sel lebihefisien danefektifdibandingkan karaginan beratmolekultinggi.Penelitian ini bertujuan untuk mengetahui kinetika reaksi pembentukan karaginan BM rendah (LMWFs) melalui proses depolimerisasi kimia (hidrolisa pada kondisi asam/H2SO4) pada kondisi operasi (pH dan suhu) optimum. Proses hidrolisa dilakukan selama 2 jam kemudiansampel diambil per 15 menit untuk dianalisis berat molekulnya. Pada penelitian ini menggunakan perbandingan karaginan  dan air (0,6 g :1000 mL),dengan variasi pH dan variasisuhu. Pada pH 2 dan suhu operasi 70°C diperoleh kondisi optimaldengan nilai konstanta kecepatan reaksi depolimerisasi k = 9,72×10-12/detik.
Prototype Penyimpanan Buah dan Sayur Menggunakan Ozon dan Metode Evaporative Cooling sebagai Sistem Pendingin Aji Prasetyaningrum; Muqsit Bramantiya; Alwi Meidianto; Pajar Saputra; Fauzia Dara Qonita; Nadia Sevi Ardiana
Jurnal Aplikasi Teknologi Pangan Vol 6, No 1 (2017): Februari 2017
Publisher : Indonesian Food Technologists

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (730.331 KB) | DOI: 10.17728/jatp.213

Abstract

Buah dan sayur merupakan bahan pangan yang bernilai gizi tinggi dan sangat bermanfaat bagi kesehatan. Namun, selama penyimpanan terjadi penurunan kualitas pada buah dan sayur yang disebabkan oleh tumbuhnya bakteri dan mikroorganisme. Metode pengawetan yang efektif, hemat energi dan ramah lingkungan dibutuhkan untuk memperpanjang masa simpan buah dan sayur tersebut. Penelitian ini bertujuan untuk menghasilkan sebuah prototype untuk mengatasi permasalahan tersebut. Prototype yang dirancang memanfaatkan ozon dan evaporative cooling untuk sistem pendinginan. Reaktor DBD dengan konfigurasi elektrode jaring-jaring digunakan untuk menghasilkan ozon sebagai desinfektan. Pembangkitan ozon membutuhkan daya total sebesar 15 watt. Pot refrigerator digunakan sebagai sistem pendingin hemat energi. Kondisi pada tempat penyimpanan, jumlah bakteri dan kondisi fisik pada buah dan sayur digunakan untuk menguji prototype. Prototype yang dihasilkan mampu mencapai suhu 25oC dengan relative humidity sebesar 95% pada tempat penyimpanannya. Buah dan sayur dengan jumlah bakteri awal sebanyak 6,5x103 cfu/100mL mampu berkurang menjadi 3,5x103 cfu/100mL setelah dicuci menggunakan ozon. Setelah penyimpanan selama tiga hari jumlah bakterinya menjadi 5,6x103 cfu/100mL, sedangkan variabel kontrol mencapai 16,6x103 cfu/100mL. Treatment yang dilakukan mampu menghambat perkembangan bakteri hingga dua kali lipatnya. Prototype yang dihasilkan mampu meningkatkan massa buah dan sayur dengan tampilan yang lebih segar dibanding variabel kontrol setelah disimpan selama tiga hari.Fruits and vegetables were a food of high nutritional value and were beneficial to health. However, after the harvest and during storage there was a decrease in the quality of fruits and vegetables caused by the growth of bacteria and microorganisms. This study aimed to produced a prototype to overcome these problems. Prototype designed utilizing ozone and evaporative cooling for refrigeration. The conditions at the storage place, the number of bacteria and the physical condition of the fruit and vegetables were used to test the prototype. The resulting prototype capable of reached temperatures of 25oC with a relative humidity of 95% in storage. Fruits and vegetables with the initial bacterial counts as much as 6.5x103 cfu/ml was able to be reduced to 3.5x103 cfu/ml after being washed using ozone. After storage for three days the amount of bacteria into 5.6x103 cfu/ml, whereas the control variable reached 16.6x103 cfu/ml. Treatment was carried out and could inhibit the growth of bacteria up to twice as much. The resulting prototype was able to increase the mass of fruits and vegetables with a fresh look compared to the control variable after being stored for three days.
PENGUATAN USAHA MIKRO DAN KECIL KERUPUK KULIT IKAN CAP MANTAP DI MLATIBARU, SEMARANG DALAM UPAYA PENCAPAIAN SUSTAINABLE DEVELOPMENT GOALS (SDGs) Dessy Ariyanti; Bakti Jos; Andri Cahyo Kumoro; Aji Prasetyaningrum; Diah Susetyo Retnowati
Jurnal Pasopati : Pengabdian Masyarakat dan Inovasi Pengembangan Teknologi Vol 4, No 1 (2022)
Publisher : Fakultas Teknik Universitas Diponegoro

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Abstract

Peran usaha mikro, kecil, dan menengah (UMKM) untuk merealisasikan tujuan pembangunan Berkelanjutan (Sustainable Development Goals SDGs) terutama Tujuan 8 yaitu  mendukung pertumbuhan ekonomi yang inklusif dan berkelanjutan, tenaga kerja penuh dan produktif dan pekerjaan yang layak bagi semua di Indonesia sangat besar. Salah satu UMK yang berada di daerah Mlati Baru, Kota Semarang adalah UMK Kerupuk Kulit Ikan Cap Mantap. UMK ini didirikan oleh Bapak Afnan Abdul Syaid pada tahun 2015. UMK ini memerlukan pendampingan sehingga dapat lebih berdaya dan berkembang. Tantangan yang dialami oleh UMK Kerupuk Kulit Ikan Cap Mantap ini adalah proses produksi yang masih mengandalkan cuaca, terutama di musim hujan, proses pengeringan kulit ikan basah sulit dilakukan dan waktu yang dibutuhkan menjadi sangat lama. Tantangan yang kedua adalah keterbatasan alat untuk packing sehingga kerupuk menjadi mudah rusak dan turun kualitasnya. Tantangan yang selanjutnya adalah pemasaran yang selama ini hanya dilakukan secara konvensional yaitu dijajakan di beberapa toko oleh-oleh dan supermarket. Pencapaian target tersebut diupayakan dengan berbagai metode dan kegiatan yang telah disusun yaitu survey awal, riset pasar, analisa SWOT, penyusunan strategi penguatan dan pendampingan, dimana Kegiatan-kegiatan tersebut ditargetkan untuk menghasilkan: Data UMK Kerupuk Kulit Ikan Cap Mantap, Data terbaru hasil riset pasar usaha yang serupa, Analisa SWOT dari UMK Kerupuk Kulit Ikan Cap Mantap, Strategi Penguatan Kerupuk Kulit Ikan Cap Mantap. Luaran yang ingin dicapai pada kegiatan ini adalah pengetahuan tepat guna yang dapat  diimplementasikan oleh UMK Kerupuk Kulit Ikan Cap Mantap di Mlatibaru, Semarang dalam upaya peningkatan kapasitas produksi dan pemasaran dari produk yang dihasilkan. Kata kunci : UMKM, kerupuk kulit ikan, pemberdayaan
Sequential Microwave-Ultrasound Assisted Extraction of Flavonoid from Moringa oleifera: Product Characteristic, Antioxidant and Antibacterial Activity Aji Prasetyaningrum; Bakti Jos; Ratnawati Ratnawati; Nur Rokhati; Teguh Riyanto; Gian Restu Prinanda
Indonesian Journal of Chemistry Vol 22, No 2 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.65252

Abstract

Moringa oleifera leaves contain secondary metabolites in flavonoid compounds known to prevent several diseases. Therefore, appropriate extraction methods are required to produce extracts with a high yield of flavonoids from Moringa. In this study, the extraction from Moringa leaves was carried out using the sequential microwave/ultrasound-assisted extraction (MUAE) method compared with sequential ultrasound/microwave (UMAE), microwave (MAE), ultrasound (UAE), and maceration (ME). The effects of the time, temperature, and percentage of ethanol were studied on total flavonoid content using AlCl3 colorimetric assay. The extracts were analyzed by Scanning Electron Microscopy (SEM), Fourier Transforms Infrared Spectrophotometry (FTIR), and High-Performance Liquid Chromatography (HPLC). The antioxidant and antibacterial activities were tested using DPPH-scavenging and disc diffusion methods. The results of SEM surface analysis on various extraction methods show differences on each surface. The FTIR spectrum showed the presence of flavonoid O–H at 3200 cm–1, C=O at 1621 cm–1, and C–O at 1019 cm–1. In the results of HPLC, MUAE extracts 16.70 mg/ 100 g flavonoid quercetin at the retention time of 4.5 min, with the highest total flavonoids (2.89 mg QE/g), the highest antioxidant activity (IC50 72.31 µg/mL), and highest antibacterial activity (S. aureus 7 mm, E. coli 2 mm).
Simultaneous Effect Of Temperature And Time Of Deacetylation On Physicochemical Properties Of Glucomannan Dyah Hesti Wardhani; Fatoni Nugroho; Nita Aryanti; Aji Prasetyaningrum
ASEAN Journal of Chemical Engineering Vol 18, No 1 (2018)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (985.447 KB) | DOI: 10.22146/ajche.49541

Abstract

The presence of acetyl group in the backbone of water-soluble glucomannan is responsible for its solubility. This solubility requires being modified to support glucomannan application as an encapsulant. Removing the group by deacetylation reduces the solubility. This work was aims to study simultaneous effect of temperature and time of deacetylation on glucomannan physicochemical properties. The deacetylation was conducted in ethanol using Na2CO3 at various times (2, 4, 8, 16, 24 and 28 h) and temperatures (room temperature, 40, 50, and 60°C). The deacetylated samples were subject to degree of deacetylation (DD) as well as solubility and swelling analysis in pH 1.2 and 6.8. DD was in positive correlation with deacetylation time and temperature. The solubility of the deacetylated glucomannan at both pHs decreased along with the deacetylation time. A reverse trend was found for swelling determination at both pHs. Increasing deacetylation temperature showed a positive impact in swelling determination but not occuring on the solubility. Interestingly, the swelling and solubility were lower at pH 1.2 than those at pH 6.8. These results showed physicochemical of deacetylated glucomannan was pH sensitive, hence have a potency as an excipient of controlled-release drug delivery system.
Copper and Lead Ions Removal by Electrocoagulation: Process Performance and Implications for Energy Consumption Aji Prasetyaningrum; Dessy Ariyanti; Widayat Widayat; Bakti Jos
International Journal of Renewable Energy Development Vol 10, No 3 (2021): August 2021
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2021.31665

Abstract

Electroplating wastewater contains high amount of heavy metals that can cause serious problems to humans and the environment. Therefore, it is necessary to remove heavy metals from electroplating wastewater. The aim of this research was to examine the electrocoagulation (EC) process for removing the copper (Cu) and lead (Pb) ions from wastewater using aluminum electrodes. It also analyzes the removal efficiency and energy requirement rate of the EC method for heavy metals removal from wastewater. Regarding this matter, the operational parameters of the EC process were varied, including time (20−40 min), current density (40−80 A/m2), pH (3−11), and initial concentration of heavy metals. The concentration of heavy metals ions was analyzed using the atomic absorption spectroscopy (AAS) method. The results showed that the concentration of lead and copper ions decreased with the increase in EC time. The current density was observed as a notable parameter. High current density has an effect on increasing energy consumption. On the other hand, the performance of the electrocoagulation process decreased at low pH. The higher initial concentration of heavy metals resulted in higher removal efficiency than the lower concentration. The removal efficiency of copper and lead ions was 89.88% and 98.76%, respectively, at 40 min with electrocoagulation treatment of 80 A/m2 current density and pH 9. At this condition, the specific amounts of dissolved electrodes were 0.2201 kg/m3, and the energy consumption was 21.6 kWh/m3. The kinetic study showed that the removal of the ions follows the first-order model.
UV Irradiation and Ozone Treatment of κ-Carrageenan: Kinetics and Products Characteristics Aji Prasetyaningrum; Widayat Widayat; Bakti Jos; Yudhy Dharmawan; Ratnawati Ratnawati
Bulletin of Chemical Reaction Engineering & Catalysis 2020: BCREC Volume 15 Issue 2 Year 2020 (August 2020)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.15.2.7047.319-330

Abstract

The low molecular weight (LMW) of sulfated polysaccharides including k-carrageenan, is shows a wide spectrum of biological activities. This research investigates the influence of UV irradiation, ozone (O3), and the combination of O3/UV methods on the depolymerization of k-carrageenan. The depolymerization kinetics of k-carrageenan using the Advanced Oxidation Process (UV/O3) was also studied. Furthermore, the intrinsic viscosity method was used to determine the average molecular weight of the research sample, and a mathematical model was developed to predict the kinetic rate constant, as a function of ozone dosage and UV irradiation intensity. Therefore, the physicochemical and morphological properties of the degraded k-carrageenan were analyzed by FT-IR, SEM, and XRD. The intrinsic viscosity k-carrageenan decreases with increasing UV light intensity and ozone concentration. The combination of UV/O3 treatment appeared to be more effective than the individual approaches, as the highest kinetic rate constant for depolymerization was 1.924×10-4 min-1, using 125 mg/L ozone concentration and 40 mW/cm2 of UV lamp intensity. This research also evaluated the relationship between various experimental conditions, including UV lamp power dissipation and ozone concentration on the reaction kinetics model, and the results suggest that lower effect is contributed by UV irradiation intensity. In addition, FT-IR spectra showed the absence of any significant change in the functional properties of k-carrageenan treated with UV and O3 processes, although the morphological properties of the LMW k-carrageenan were rougher and more porous than the native k-carrageenan. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
Kinetics and Thermodynamics of Ultrasound-Assisted Depolymerization of κ-Carrageenan Ratnawati Ratnawati; Aji Prasetyaningrum; Dyah Hesti Wardhani
Bulletin of Chemical Reaction Engineering & Catalysis 2016: BCREC Volume 11 Issue 1 Year 2016 (April 2016)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.11.1.415.48-58

Abstract

The ultrasound-assisted depolymerization of κ-carrageenan has been studied at various temperatures and times. The κ-carrageenan with initial molecular weight of 545 kDa was dispersed in water to form a 5 g/L solution, which was then depolymerized in an ultrasound device at various temperatures and times. The viscosity of the solution was measured using Brookfield viscometer, which was then used to find the number-average molecular weight by Mark-Houwink equation. To obtain the kinetics of κ-carrageenan depolymerization, the number-average molecular weight data was treated using midpoint-chain scission kinetics model. The pre-exponential factor and activation energies for the reaction are 2.683×10-7 mol g-1 min-1 and 6.43 kJ mol-1, respectively. The limiting molecular weight varies from 160 kDa to 240 kDa, and it is linearly correlated to temperature. The results are compared to the result of thermal depolymerization by calculating the half life. It is revealed that ultrasound assisted depolymerization of κ-carrageenan is faster than thermal depolymerization at temperatures below 72.2°C. Compared to thermal depolymerization, the ultrasound-assisted process has lower values of Ea, ΔG‡, ΔH‡, and ΔS‡, which can be attributed to the ultrasonically induced breakage of non-covalent bonds in κ-carrageenan molecules. 
Co-Authors . Widayat Aat Zaki Mubarok Al Farrel A. Raemas Alwi Meidianto Andri Cahyo Kumoro Bakti Jos Denni Kartika Sari Dessy Ariyanti Dessy Ariyanti Diah Susetyo Retnowati Dyah Arum Kusumaningtyas Dyah Hesti Wardhani Fadlillah Fani Fatoni Nugroho Fauzia Dara Qonita Fitri Lafifa Gian Restu Prinanda Indrawati Dwi Paramita Inggrid K. Wardhani M. Djaeni Muqsit Bramantiya Nadia Sevi Ardiana Nita Aryanti Noer Abyor Handayani Novianto D K Nur Rokhati Nurfiningsih Nurfiningsih Nurul Asiah Pajar Saputra Purbo Suseno Ratnawati Ratnawati Ressa Puspita Dewi Sadam Arrois Samir Badres Teguh Riyanto Widayat Widayat Y. Dinarianasari Yudhy Dharmawan