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All Journal Jurnal Teknik Kimia USU Jurnal Rekayasa Bahan Alam dan Energi Berkelanjutan Jurnal Teknik Kimia USU
Islam, Livya Safira
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Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Engineering Environmental Science Industrial & Manufacturing Engineering Materials Science & Nanotechnology

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Pengaruh Suhu Ekstraksi dan Kecepatan Pengadukan terhadap Karakteristik Crude Ekstrak Stevia Dewi, Luthfi Kurnia; Milenia, Rohmah; Islam, Livya Safira; Ismuyanto, Bambang
Jurnal Teknik Kimia USU Vol. 13 No. 2 (2024): Jurnal Teknik Kimia USU
Publisher : Talenta Publisher (Universitas Sumatera Utara)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jtk.v13i2.17131

Abstract

Stevia is a natural sweetener that is 250-300 times sweeter than sucrose and is low in calories. Stevia sweeteners are obtained from the extraction of stevia leaves. This study aims to determine the effects of temperature and stirring speed on the characteristics of crude stevia extract (yield, brix value, and IR spectrum). Maceration extraction was conducted with 70% ethanol for 1 hour, varying the temperature (28 ℃, 40 ℃, 55 ℃) and stirring speed (0 rpm, 50 rpm, 100 rpm, 150 rpm). The results showed that a temperature of 40 ℃ produced the highest yield at each stirring speed. The yield increased with the increase in stirring speed at each extraction temperature. The highest brix value was obtained at 55 ℃ and a stirring speed of 150 rpm. The IR spectrum results showed that the functional groups in the crude stevia extract were almost identical to those in commercial stevia.
Pengaruh Suhu Ekstraksi dan Kecepatan Pengadukan terhadap Karakteristik Crude Ekstrak Stevia Dewi, Luthfi Kurnia; Milenia, Rohmah; Islam, Livya Safira; Ismuyanto, Bambang
Jurnal Teknik Kimia USU Vol. 13 No. 2 (2024): Jurnal Teknik Kimia USU
Publisher : Talenta Publisher (Universitas Sumatera Utara)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jtk.v13i2.17131

Abstract

Stevia is a natural sweetener that is 250-300 times sweeter than sucrose and is low in calories. Stevia sweeteners are obtained from the extraction of stevia leaves. This study aims to determine the effects of temperature and stirring speed on the characteristics of crude stevia extract (yield, brix value, and IR spectrum). Maceration extraction was conducted with 70% ethanol for 1 hour, varying the temperature (28 ℃, 40 ℃, 55 ℃) and stirring speed (0 rpm, 50 rpm, 100 rpm, 150 rpm). The results showed that a temperature of 40 ℃ produced the highest yield at each stirring speed. The yield increased with the increase in stirring speed at each extraction temperature. The highest brix value was obtained at 55 ℃ and a stirring speed of 150 rpm. The IR spectrum results showed that the functional groups in the crude stevia extract were almost identical to those in commercial stevia.
Studi Potensi Minyak Sereh Wangi Sebagai Alternatif Bahan Aditif Pada Bahan Bakar Minyak Milenia, Rohmah; Islam, Livya Safira; Ihsan, Muhammad; Sarosa, Aji Hendra
Jurnal Rekayasa Bahan Alam dan Energi Berkelanjutan Vol. 6 No. 1 (2022)
Publisher : Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.rbaet.2022.006.01.02

Abstract

Bahan bakar jenis pertalite merupakan salah satu bahan bakar produksi Pertamina dengan RON 90. Sedangkan, solar memiliki angka setana 48 dengan kualitas di bawah pertalite. Efektifitas bahan bakar dapat ditingkatkan dengan penggunaan aditif. Salah satu terobosan terbaru dalam penggunaan aditif ialah minyak sereh wangi. Minyak sereh wangi memiliki karakteristik yang menyerupai bahan bakar. Selain itu, minyak sereh wangi mengandung senyawa oksigenat yaitu sitronelal, sitronelol, geraniol yang berpotensi untuk menyempurnakan pembakaran bahan bakar dengan mengoksidasi karbon monoksida menjadi karbon dioksida. Jurnal ini meninjau keefektifan minyak sereh wangi sebagai aditif pada bahan bakar. Bahan bakar minyak akan ditinjau, diikuti peninjauan potensi minyak sereh wangi sebagai bahan aditif pada bahan bakar. Selain itu, pengaruh penambahan bahan aditif minyak sereh wangi terhadap nilai kalor, angka oktan, emisi karbon monoksida, serta efek pada mesin kendaraan juga ditinjau. Dari studi literatur ini, didapatkan bahwa penambahan minyak sereh wangi dalam konsentrasi yang tepat dapat meningkatkan nilai kalor dan angka oktan bahan bakar. Kenaikan ini bervariasi pada setiap konsentrasi zat aditif di dalam bahan bakar dan dipengaruhi pula oleh kombinasi zat aditif yang digunakan. Emisi karbonmonoksida dan kerak yang dihasilkan pada kendaraan bermotor berbahan bakar pertalite dengan penambahan minyak sereh wangi dalam volume yang tepat dapat berkurang.
Co-Authors Aji Hendra Sarosa Bambang Ismuyanto Luthfi Kurnia Dewi, Luthfi Kurnia Milenia, Rohmah Muhammad Ihsan