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All Journal Jurnal Riset Kimia KACANEGARA Jurnal Pengabdian pada Masyarakat JSMARTech : Journal of Smart Bioprospecting and Technology Jurnal Rekayasa Proses
Dyah Ratna Wulan
Jurusan Teknik Kimia, Politeknik Negeri Malang, Jawa Timur
Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Education Materials Science & Nanotechnology Medicine & Pharmacology Neuroscience

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Ekstrak Kafein sebagai Inhibitor Korosi Alami pada Logam Aluminium dalam Media Larutan Asam Sulfat dan Biosolar Marinda Sukmawanta, Shafara Najla; Wulan, Dyah Ratna; Widjajanti, Kristina; Azkiya, Noor Isnaini; Maryanty, Yanty
Jurnal Riset Kimia Vol 13, No 1 (2022): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v13i1.488

Abstract

This research, the caffeine extract of arabica coffee beans, cacao beans, and black tea leaves will be tested as a corrosion inhibitor on aluminium in an acidic environment and in biodiesel containing acid. This condition resembles the metabolism of microorganisms in biodiesel which produces H2SO4 as one of the causes of corrosion. Arabica coffee, cacao beans and black tea are natural organic ingredients containing caffeine which can inhibit corrosion. In the maceration process used a variable ratio of 70% ethanol solvent with organic matter, namely 225 grams of organic matter with 450 grams of ethanol and 150 grams of organic matter with 450 grams of ethanol. Concentration of caffeine extract from arabika coffee, cacao beans, and black tea leaves was obtained based on HPLC analysis at an effluent rate of 0.8 mL/min. The corrosion inhibition efficiency test on aluminium was observed at 0, 1, 4, 7 and 10 days of immersion. The previously used aluminium has been corroded with 12% H2SO4. The corrosion inhibition efficiency test on aluminium was observed at 0, 1, 4, 7 and 10 days of immersion. The best inhibitor results on aluminium soaked in biosolar containing 12% H2SO4 is tea 1.234,313 ppm with a corrosion rate of 1.6x10-4 g/cm2 day on day 1 to 2.5x10-4 g/ cm2 day on day 10 with an inhibition efficiency of 99%. While the aluminium soaked in H2SO4 12% is tea containing caffeine of 684.373 ppm with a corrosion rate of 1.3 x10-4 g/ cm2 day on day 1 to 3.3x10-4 g/ cm2 day on day 10 with an inhibition efficiency of 64%. The longer the immersion time of aluminium in H2SO4 media with the addition of organic inhibitors, the lower the corrosion rate value because the inhibitors form a layer that protects the aluminium.
Pengaruh ekstrak kafein sebagai inhibitor laju korosi dan efisiensi inhibisi pada baja dalam larutan asam sulfat dan biosolar Maryanty, Yanty; Ifvournamasari, Adinda Dwi; Widjajanti, Kristina; Wulan, Dyah Ratna; Azkiya, Noor Isnaini
Jurnal Rekayasa Proses Vol 17 No 1 (2023): Volume 17, Number 1, 2023
Publisher : Jurnal Rekayasa Proses

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.71831

Abstract

Telah dilakukan penelitian tentang pengujian ekstrak kafein dari kopi arabika, coklat, dan daun teh hitam sebagai inhibitor laju korosi pada baja dalam lingkungan yang mengandung asam dan dalam biosolar yang mengandung asam. Penyimpanan biosolar B30 dalam tangki dalam waktu lama mengakibatkan penurunan pH, pembakaran tidak sempurna, dan korosi pada tangki penyimpanan yang diduga disebabkan oleh komposisi konsorsium bakteri. Pada penelitian sebelumnya hasil penelitian menunjukkan bahwa genus yang dominan merupakan bakteri penghasil asam yang diduga menjadi penyebab penurunan kadar pH biosolar B30 selama masa penyimpanan. Berdasarkan Analisa metagenomik pada biosolar B30 ditemukan genus Eubacteria merupakan bakteri penyebab korosi pada kondisi anaerob. Sehingga pada penelitian dibuat kondisi keasaaman yang dihasilkan oleh mikroorganisme dengan penambahan H2SO4 12%. Ekstrak kafein diperoleh dari proses maserasi dengan variabel perbandingan pelarut etanol 70% : bahan organik yaitu 1 : 2 dan 1 : 3. Uji ekstrak kafein dilakukan dengan metode HPLC pada laju effluent 0,8 mL/min. Sedangkan uji efisiensi inhibisi korosi pada baja diamati pada kurun waktu perendaman 0, 1, 4, 7 dan 10 hari. Baja yang digunakan sebelumnya telah dikorosikan dengan H2SO4 12%. Hasil inhibitor terbaik pada baja yang direndam H2SO4 12% didapatkan inhibitor terbaik yaitu kopi 2100,793 ppm dengan laju korosi sebesar 84,7x10-4 g/cm2 hari pada hari ke-1 menjadi 75,5x10-4 g/cm2 hari pada hari ke-10 dengan efisiensi inhibisi sebesar 80%. Sedangkan pada baja yang direndam biosolaryang mengandung H2SO4 12% didapatkan inhibitor terbaik yaitu kopi 2.100,793 ppm dengan laju korosi sebesar 0,3x10-4 g/cm2 hari pada hari ke-1 menjadi 0,2x10-4 g/cm2 hari pada hari ke-10 dengan efisiensi inhibisi sebesar 100%. Semakin lama waktu perendaman baja dalam media H2SO4 maupunbiosolar yang mengandung H2SO4 12% dengan penambahan inhibitor organik maka nilai laju korosi semakin rendah karena inhibitor membentuk lapisan yang melindungi baja.
Pelatihan pembuatan produk teh herbal olahan toga pada UMKM di lingkungan ‘Aisyiyah Kota Malang Dewajani, Heny; Susanti, Ari; Hakim, Arif Rahman; Takwanto, Anang; Wulan, Dyah Ratna; Hidayati, Mutia Dewi
KACANEGARA Jurnal Pengabdian pada Masyarakat Vol 8, No 4 (2025): November
Publisher : Institut Teknologi Dirgantara Adisutjipto

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28989/kacanegara.v8i4.2744

Abstract

UMKM memiliki peran yang sangat penting dalam mendukung perekonomian nasional. Di Kota Malang, ibu-ibu pelaku UMKM sering menghadapi ketidakpastian pendapatan, dengan kebanyakan masih menjalankan usaha kecil di tingkat rumah tangga. Tim Pengabdian kepada Masyarakat (PPM) dari Jurusan Teknik Kimia Politeknik Negeri Malang berupaya memberikan solusi untuk meningkatkan pendapatan masyarakat dengan memberikan informasi terkait manfaat Tanaman Obat Keluarga (TOGA) serta peranannya dalam kehidupan sehari-hari, termasuk cara pembuatannya dalam skala industri rumah tangga. Kegiatan ini berupa demonstrasi dan sesi tanya jawab, yang mencerminkan dukungan nyata dari pihak kampus terhadap Tri Dharma Perguruan Tinggi. Berdasarkan hasil pre dan post-test sebanyak 70% mitra menunjukkan kesetujuannya terhadap peningkatan pengetahuan dan ketrampilan mereka sebagai Solusi atas permasalahan yang terjadi. Selain itu, diharapkan setelah kegiatan ini selesai maka kelompok ibu-ibu pelaku UMKM di lingkungan ‘Aisyiyah Kota Malang dapat menjadi produsen Teh TOGA berkualitas dan menjadikan produksi Teh TOGA sebagai usaha yang potensial di masa depan.
Efektifitas Reaksi Transesterifikasi Minyak Kelapa dan Sereh untuk Pembuatan Perisa Alami dengan Biokatalisator Lipase serta Penggunaan Ultrasonik Moentamaria, Dwina; Amalia, Nabila Rizki; Rosita Dwi Chrisnandari; Irfin, Zakijah; Wulan, Dyah Ratna
Jurnal Riset Kimia Vol. 15 No. 1 (2024): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v15i1.641

Abstract

In general, flavor are synthesis through enzymatic hydrolysis and esterification reactions (up to 20 hours) using commercial ingredients based on free fatty acids and alcohol. Efficient endeavors utilizing enzymatic transesterification to expedite reactions are necessary to acquire flavored products. Substrates may originate from commercial or natural sources abundant in fatty acids and alcohol. Commercial fatty acids and alcohol (geraniol) are readily available in pure forms. Alternatively, fatty acids can be sourced from coconut oil, while geraniol can be derived from lemongrass oil, which is more cost-effective compared to commercial ingredients. Ultrasonics have emerged as a means to expedite enzymatic. The objective of this study is to investigate the impact of ultrasonic power and transesterification reaction time between coconut oil and geraniol on geraniol conversion. Utilizing lipase (415.99 U/g), coconut oil was subjected to transesterification with commercially obtained pure geraniol in a 1:3 weight ratio, conducted in an ultrasonic tank filled with water. Reaction durations spanned 30, 60, 90, 120, and 150 minutes, with ultrasonic powers set at 50, 70, and 90 watts. The study findings elucidated that the highest geraniol conversion rate of 50.59% was achieved with 70 watts of ultrasonic power over a 90-minute period. These optimal conditions were subsequently applied to transesterify coconut oil with geraniol from lemongrass oil, yielding a conversion rate of 90.29%. This finding demonsttrate the posibility of employing coconut oil and lemongrass oil in a one-stage transesterification process to produce natural flavors via enzymatic lipase catalysis expedited by ultrasonic technology, facilitating swift reaction times.
Milk-Clotting Enzymes from Rhizomucor miehei and Rhizomucor pusillus Grown on Wheat Bran–Molasses Medium: Production Conditions and Preliminary Application in Mozzarella Cheese Making Maryanty, Yanty; Mareta, Arien Putri; Rahmasari, Amalia; Wulan, Dyah Ratna; Susanti, Ari; Lusiyani, Ria; Azkiya, Noor Isnaini
JSMARTech: Journal of Smart Bioprospecting and Technology Vol. 7 No. 2 (2026): JSMARTech Volume 7, No 2, 2026
Publisher : JSMARTech

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jsmartech.2026.007.02.41

Abstract

Mozzarella cheese manufacture depends on milk-clotting enzymes (rennet), conventionally obtained from calf abomasum at relatively high cost. This preliminary study evaluated Rhizomucor miehei and Rhizomucor pusillus (formerly Mucor miehei and Mucor pusillus) grown on a wheat bran–molasses (1:1) medium as a source of microbial rennet and assessed their crude extracts in mozzarella cheese making. Enzyme production was evaluated using a full factorial design with incubation temperature (34 and 37 °C), medium pH (5, 6, and 6.5), and incubation time (4, 6, 7, 8, and 10 days) in duplicate. Milk-clotting activity (MCA), proteolytic activity (PA), and MCA/PA ratio were analyzed using three-way ANOVA followed by Tukey's test. Incubation temperature significantly affected MCA of both strains (p < 0.01). The highest MCA was obtained at 37 °C, 6,495.89 ± 241.52 U/mL for R. miehei (pH 6.5, 7 days) and 7,246.84 ± 81.69 U/mL for R. pusillus (pH 6, 8 days), with clotting times of approximately 83–92 s. Incubation at 37 °C doubled PA of R. miehei, resulting in a higher MCA/PA ratio at 34 °C, whereas R. pusillus showed similar ratios at both temperatures. Mozzarella produced with the highest-MCA extracts yielded 3.19%, significantly lower than 3.27% obtained with commercial rennet, although the absolute difference was small. Yields were substantially below typical cow's milk mozzarella yields, suggesting that the low yield was more likely related to the cheese-making procedure, particularly preacidification to pH 5.0, than to the enzyme source. Extract-based cheeses had lower moisture (48.9–49.6%) and meltability than the control. Both strains produced milk-clotting enzymes using low-cost wheat bran–molasses substrate. However, process optimization is needed before economic feasibility can be assessed.
Co-Authors Amalia, Nabila Rizki Ari Susanti Arif Rahman Hakim Dewajani, Heny Hidayati, Mutia Dewi Ifvournamasari, Adinda Dwi Irfin, Zakijah Lusiyani, Ria Mareta, Arien Putri Marinda Sukmawanta, Shafara Najla Noor Isnaini Azkiya, Noor Isnaini Rahmasari, Amalia Rosita Dwi Chrisnandari Takwanto, Anang Widjajanti, Kristina Yanty Maryanty, Yanty