Zuhaili Idham

Extraction of peanut skin oil by modified supercritical carbon dioxide: Empirical modelling and optimization

ABSTRACT Peanut skin is a waste by-product from peanut industries. It is rich in antioxidants and bioactive compounds. Therefore, the objective of this study was to empirically model and optimize supercritical CO2 extraction of oil from peanut skin. The extraction conditions were pressure (100, 200 and 300 bar), temperature (313, 328 and 343 K) and rate of modifier ethanol (0.075, 0.15 and 0.225 mL/min). The extraction process was subsequently examined using modified Brunner and Esquivel models. The optimum conditions for extraction peanut skin oil were 279 bar, 70°C and rate of modifier of 7.5% with a maximum yield of peanut skin oil of 0.83 g and initial slope of 0.568 g/min.

Optimisation of squalene from palm oil mesocarp using supercritical carbon dioxide

A promising technique of Green Supercritical Carbon Dioxide (SC-CO2) process was developed for the extraction of squalene from palm oil mesocarp. In this study, the green SC-CO2 was compared with the conventional Soxhlet extraction for quantify the best extraction method. The independent variables in SC-CO2 were selected as follows: temperature (45-75°C), pressure (16-30 MPa) and CO2 flow rate (2-5 ml/min). The responses are oil yield and the concentration of squalene. On the other hands, the conventional soxhlet extraction condition was type of solvents. Furthermore, the conditions of SC-CO2 extraction for squalene and oil yield were optimized by response surface methodology (RSM) following Box-Behnken Design (BBD). The optimum conditions were at pressure (16 MPa), temperature (45.01°C) and CO2 flow rate (2 ml/min) and the concentration of squalene was 0.506%. Meanwhile for soxhlet extraction method showed the concentration of squalene was 0.143% with chloroform. In overall, the results indicated the green SC-CO2 was the best an alternative technique.

Effect of operating conditions on catechin extraction from betel nuts using supercritical CO2-methanol extraction

ABSTRACT In this work, the effect of extraction parameters on catechin extraction from betel nuts was studied. The supercritical carbon dioxide extraction parameters were pressure, temperature, and solvent flow rate while using average particle size of 177.5 μm and 5% (v/v) methanol as modifiers. Detection and quantification of catechin were achieved using HPLC analysis. The highest amount of extract and catechin concentration were 34.00 mg extract/g sample and 565.38 ppm of catechin obtained at 30 MPa, 70°C, and 4 mL/min. The results given by optimization tools suggest the same operating conditions with less than 3% difference.

Optimisation of supercritical CO2 extraction of red colour from roselle (Hibiscus Sabdariffa Linn.) calyces

Roselle (Hibiscus sabdariffa Linn.) is a local tropical plant widely cultivated in Malaysia. Roselle produces red edible calyces which contain intense red pigments of anthocyanins. Supercritical fluid extraction with carbon dioxide (CO2) is a particularly suitable isolation method for natural materials and gives an alternative to replace the mass usage of non-polar organic solvents in conventional methods. The advantage of using CO2 as solvent is that no organic solvent residual inside the extracted sample since CO2 is in gas form at room temperature. The red colour extract by using CO2 is easier to be separated by decompression and has high recovery percentage. The objective of this research was to optimise the supercritical carbon dioxide (SC-CO2) extraction conditions for obtaining the maximum yield of red colour extract. SC-CO2 extraction of red colour of roselle was performed with ethanol as modifier at the pressures of 8, 10 and 12 MPa, temperatures of 50, 60 and 70 °C while the percentage of modifier flow rates was at 5, 7.5 and 10 %. Full 33 factorial design was used to optimise operating conditions for the extraction yield of roselle calyces in SC-CO2.The other parameters were kept constant, such as total flow rate of CO2 and modifier (6 mL/min), ratio of modifier (75 % of ethanol), the average particle size used (350 μm) and extraction regime (70 min). The findings revealed that the extraction yield was significantly influenced by three main effects investigated in this study, with p-value smaller than 0.05. The optimum operating conditions obtained for SC-CO2 extraction of red colour extract were 8.90 MPa, 70 °C, and 9.49 % with predicted percentage yield of 26.73 %.