Analisa Senyawa Volatil Kopi Robusta Menggunakan Gas Chromatography (GC) dengan Metode Preparasi Sampel Destilasi Uap-Ekstraksi Pelarut
Abstract
This research was conducted to determine the profile of volatile compounds,
separation performance using Gas Chromatography-Flame Ionization Detector
(GC-FID), and to determine the aromatic components of robusta coffee. Sample
preparation methods use steam distillation and liquid-liquid extraction with
dichloromethane solvent. The robusta coffee of Sidomulyo, Garahan, and Gumitir
was distilled with temperature variations of 55°C, 65°C, and 75°C for 4 hours.
Distillate results are extracted to obtain coffee extract. The GC analysis uses a
Tr-1MS column with a temperature of an injector and detector of 250°C, the
initial temperature of oven 60°C is maintained for 2 minutes and then gradually
increased by 5°C/min to 200°C. The number of components and intensity of each
component identified in robusta coffee chromatogram profile is comparable to the
increase in distillation temperature. The higher the distillation temperature will
increase the amount of essential oil, so that more volatile compounds are
detected. Separation of components in GC by observing resolution values and
column efficiency. The separation perfomance of components within GC provides
good separation based on the result of the >1,5 resolution value and >2000
theoretical plate value. The aromatic component of volatile compounds is
identified with the Gas Chromatography-Mass Spectrometer (GC-MS). The
volatile compounds identified in robusta coffee are 29 components from aldehyde,
phenol, alcohol, acid, furan, benzene, and hydrocarbons groups.