Optimum condition for Nigella sativa seeds oil and its bioactive compound, thymoquinone (TQ) using supercritical fluid carbon dioxide extraction (SCFE-CO 2 ), were investigated. The optimization process was performed with Taguchi method and full factorial design (FFD) under the following condition: pressure (150, 200 and 250 bar), temperatures (40, 50 and 60 o C) and carbon dioxide (CO 2 ) flowrate (10, 15 and 20 g/min), in which solvent to feed (SF) ratio was set constant at 24. The highest yield of Nigella sativa seeds oil from SCFE-CO 2 process with FFD method was 12% at 250 bar, 60 o C and 20 g/min. Whereas Taguchi method was performed at 250 bar, 50 o C, 10 g/min with oil yield 11.9%. The highest thymoquinone content in Nigella sativa seeds oil from both experimental design was achieved through SCFE-CO 2 extraction condition at 150 bar, 60 o C and 20 g/min with thymoquinone content 20.8 mg/ml. In addition, conventional methods such as high pressure soxhlet with liquid CO 2 , n-hexane soxhlet and percolation with ethanol were performed with oil yield 5.8%, 19.1% and 12.4%; and thymoquinone content 8.8 mg/g oil, 6.3 mg/g oil and 5.0 mg/g oil, respectively. The analysis of variance (ANOVA) with 95% confidence interval, indicates effect of pressure on Nigella sativa seeds oil yield and thymoquinone content from SCFE-CO 2 process. The oil was then evaluated for its activity. The antibacterial activity of the oil from Taguchi Method, shows that all samples were unable to inhibit Escherichia coli O157 and Salmonella typhimurium. For other pathogenic bacterias, all samples show similar inhibition at concentration 10% oil for MRSA, 3% oil for Stapylococcus aureus and 3% oil for Bacillus subtilis.
Objective: Optimum condition for the extraction of citronella oil from citronella (Cymbopogon winterianus) using supercritical carbon dioxide (SC-CO2) was investigated.Methods: In order to determine the optimum extraction condition, a Taguchi experiment with L9 orthogonal array design was used. Effects of pressure, temperature and dynamic extraction time on citronella oil yield were investigated at levels ranging between 10-15 MPa, 35-45 °C and 60-180 min, respectively.Results: The highest citronella oil yield (3.206%) was achieved at a factor combination of 15 MPa, 50 °C and 180 min. The obtained citronella oil yield from SC-CO2 extraction was higher than that of percolation as the solvent extraction method using ethanol, which gave a citronella oil yield of 1.4%. The experimental oil yield at optimum condition was in accordance to the values predicted by a computational process using Taguchi method. Analysis of variance (ANOVA) with 95% confidence interval indicates that extraction temperature is the most significant factor in maximizing citronella oil yield, followed by dynamic extraction time and pressure.Conclusion: Optimization process for oil yield from SC-CO2extraction of citronella (Cymbopogon winterianus) was successfully performed using Taguchi L9 orthogonal array design. This study demonstrates that Taguchi method was able to simplify the experimental procedure of SC-CO2 process.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.