Process optimization of supercritical CO2 extraction of Roselle using response surface methodology

Abstract

Hibiscus sabdariffa, commonly known as Roselle, is a native plant in Malaysia that is rich with bioactive compounds. In the present study, supercritical carbon dioxide (SC-CO2) extraction of Roselle was investigated. The optimum particle size (212μm, 300μm, 425μm, 600μm, and 710μm) to obtain highest yield was pre-determined. The effects of two operating parameters, pressure (20MPa, 25MPa, and 30MPa) and temperature (40°C, 60°C, and 80°C) on extraction yield were studied using response surface methodology (RSM). From the experimental data, the optimum conditions were achieved using particle size 300μm, pressure 27.5MPa, and temperature 50.8°C. Using the optimized parameters, the highest extraction yield was predicted to be 163.26 mg-extract/g-dried sample. The validation experimental results were consistent with the predicted values.