Effect of flow rate, particle size and modifier ratio on the supercritical fluid extraction of anthocyanins from Hibiscus sabdariffa (L).

Abstract This work aims to evaluate the effects of different particle size, flow rate and modifier ratio on the extraction yield and anthocyanins content of Hibiscus sabdariffa L (Roselle) by using supercritical carbon dioxide (SC-CO 2 ) method. SC-CO 2 extraction was carried out at constant pressure and temperature, 10MPa and 70°C respectively with 75% (v/v) ethanol as a modifier. The result shows that 120 minutes was the efficient extraction time at a determination of flow rate. The trend and results for the extraction yield and anthocyanins were varied in all parameters studied. The finding shows that a low flow rate (4 ml/min), smaller particle size (200-355 µm) and high percentage ratio of modifier (10%) could obtain more anthocyanins content. Thus, the manipulation of several parameters in the SC-CO 2 extraction process could enhance the selectivity of anthocyanins extraction from the total extract.