Optimization of supercritical carbon dioxide extraction of essential oil from Amomum krevanh Pierre

Abstract

Supercritical carbon dioxide extraction of essential oil from Amomum krevanh Pierre was studied. The influence of particle sizes of the raw materials on essential oil yields was studied for the particle size range between 180 and 800 [micro]m and the maximum essential oil yield was obtained with the particle size of 250-355 [micro]m. Furthermore, the experimental design and response surface methodology was employed in order to investigate the effects of operating condition and to predict the optimal condition for supercritical carbon dioxide. The factors investigated for essential oil were operating temperature in range of 33-67 [degree Celcius], the operating pressure in range of 91-259 bar, and the extraction time in range of 20-70 min. The results showed that the main effect of operating pressure and the interaction effect between operating temperature and extraction time were significant factors for the essential oil yields. From the response surface model of the experimental data, an optimal condition for essential oil content was found to be at the temperature of 64 [degree celcius], the pressure of 277 bar, and the extraction time of 84 minutes. At this condition, the amount of essential oil yield extracted was 11.90 mg/g dry amomum. The yield obtained by SC-CO[subscript 2] extraction was higher than the amount obtained by organic solvent extraction which was 9.74 mg/g dry amomum. The major compounds obtained by SC-CO[subscript 2] were 1,8-cineole (71.65%), [beta]-pinene (8.64%), and limonene (4.77%) which were similar to that obtained by organic solvent extraction whose compositions was 1,8-cineole (70.86%), β-pinene (7.91%), and limonene (4.30%).