Supercritical fluid extraction of diosgenin from tubers of Dioscorea nipponica

Abstract Supercritical fluid extraction (SFE) was used to extract diosgenin following acid hydrolysis from Dioscorea nipponica tuber. Diosgenin determinations were carried out using capillary GC of trifluoroacetate derivatives. Highest diosgenin yields were obtained using 3100 p.s.i. (1 p.s.i. = 6894.76 Pa) pressure for 70 min, but > 82% of this yield was extracted by 40 min. Higher recoveries were obtained than by extraction using light petroleum (b.p. 40–60°C) extraction.