Indones. J. Chem., 2018, 18 (2), 235 - 241 Edi Priyo Utomo et al. 235 * Corresponding author. Tel : +62-85646464893 Email address : edipu2000@yahoo.com DOI: 10.22146/ijc.26605 Optimization of Supercritical CO2 Extraction Process to Improve the Quality of Patchouli Oil by Response Surface Methodology Approach Edi Priyo Utomo 1,* , Marina 2 , Warsito 1 , and Egi Agustian 3 1 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Brawijaya University, Jl. Veteran, Malang 65145, Indonesia 2 Department of Agroindustrial Technology, Faculty of Agriculture Technology, Brawijaya University, Jl. Veteran, Malang 65145, Indonesia 3 Research Center for Chemistry, Indonesian Institute of Sciences, Kawasan PUSPIPTEK, Serpong – 15314, South Tangerang, Banten, Indonesia Received July 17, 2017; Accepted November 1, 2017 ABSTRACT Until now, the patchouli oil is the most substantial commodity export of essential oil for Indonesia. But the price of patchouli oil is often unstable due to the quality of oil which fluctuates depending on the components. To improve the performance and quality of patchouli oil had been carried out the purification process using supercritical CO2 fluid extraction method. Optimization conditions of the extraction process were calculated using the approach of Response Surface Methodology (RSM) including the influence of independent variables such as temperature (35–45 °C), pressure (80–150 atm) and the time of extraction (60–300 min).The optimum condition was attained by using a Box- Behnken Design (BBD). Analysis of the components in the extract was carried out by using GC-MS and GC-FID to detect the changes of compositions of the oil components before and after the extraction process. The optimum condition of supercritical extraction within experimental range of the studied variables was at 38°C, 146.35 atm and 74 min for predicted oil yield of 6.41% and at 41.45 °C, 135.17 atm and 252.62 min and the predicted patchouli alcohol content was 25.34%. The extracted oil is enriched with the main components such as patchouli alcohol compared to the original patchouli oil. The results of RSM evaluation showed consistency between the variables contained in the experiment and the prediction. Keywords: supercritical CO2; patchouli oil; Response Surface Methods (RSM) ABSTRAK Sampai sekarang minyak nilam adalah komoditas eksport paling besar dari minyak atsiri Indonesia. Tetapi harga pasar minyak nilam ini seringkali tidak stabil dan mengalami fluktuasi yang disebabkan oleh kualitas dan komposisi dari komponen-komponennya. Untuk memperbaiki kualitas minyak nilam telah dilakukan proses esktraksi dengan menggunakan metoda ekstraksi fluida CO2 superkritik. Kondisi optimum proses ekstraksi diperhitungkan melalui pendekatan Metoda Permukaan Respon (MPR) dan pengaruh variable-variabel bebas meliputi temperatur (35–45 °C), tekanan (80–150 atm) dan waktu ekstraksi (60–300 menit), kemudian dievaluasi dengan menggunakan Box- Behnken Design (BBD). Komposisi komponen-komponen dalam esktrak dianalisis menggunakan GC-MS dan GC- FID baik sebelum maupun sesudah proses ekstraksi. Proses ekstraksi CO2 superkritik pada kisaran variabel yang dipelajari menunjukkan bahwa pada 38 °C, 146.35 atm dan 74 menit menghasilkan ekstrak minyak nilam optimum sebesar 6,41% sedangkan pada 41,45 °C, 135,17 atm dan 252,62 menit menghasilkan kandungan patchouli alkohol optimum sebesar 25.34%. Kata Kunci: CO2 superkritik; minyak nilam; Metoda Permukaan Respon (MPR) INTRODUCTION In Indonesia, patchouli oil is one of the most valuable commodities of essential oils exclusively exported to other countries for pharmaceutical and perfumes. According to Indonesian National Standard (SNI), the good quality of patchouli oil must be matched with SNI 06-2385-2006 [1-3] in which the physico- chemicals properties involving two type of color (yellow to reddish brown), density (0.950–0.975 at 25 °C), content of patchouli alcohol (min. 30%), and refractive index (nD 20 1.507–1.515). Especially for patchouli alcohol, this constituent is the most important chemical should be present in enough amounts to meet the