Analisa Senyawa Volatil Pada Kopi Robusta Menggunakan Gas Chromatography Dengan Metode Ekstraksi Ultrasonik

Abstract

Coffee is one of Indonesian’s commodity that widely consumed by the public. There are many types of coffee, the most known use is robusta coffee. it has volatile compound components that play an important role on determining the quality of aroma and flavor. Volatile compounds in coffee were analyzed to determine the peak profile on the chromatogram, separation performance, and confirmation volatile compound by Gas Chromatography-Mass Spectrometry (GC-MS). Analysis of volatile compounds begin with the ultrasonic extraction method using distilled water and dichloromethane solvents. The type of coffee used were Sidomulyo, Garahan, and Gumitir. Ultrasonic extraction was carried out for 30 minutes at 30ᵒC with a sample and solvent ratio of 1:9 (w/v). GC analysis results extracted with distilled water solvent in Sidomulyo coffee obtained 30 compounds, Garahan coffee 27 compounds, and Gumitir coffee 25 compounds. Coffee extracted with dichloromethane solvent on Sidomulyo coffee obtained 25 compounds, Garahan coffee 18 compounds and Gumitir coffee 24 compounds. The best separation performance or resolution (Rs) was obtained by Gumitir coffee extracted using distilled water (5.93 ± 1.09). GC-Flame Ionization Detector (FID) results were confirmed using GC-MS to determine the components in each compound. GC-MS confirmation showed 30 compounds identified in 12 groups, namely hydrocarbon, alcohol, furan, esther, phenol, pyrazine, pyrrole, aldehyde, and ketone groups. The most common compound found was caffeine. The results obtained from the three types of coffee showed that coffee extracted using distilled water solvent obtained a better number of compounds, intensity, and separation performance, compared to coffee extracted using dichlorormethane solvent.