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 ºC, 60 ºC, and 80 ºC) 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 ºC. 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.