| Echinacoside and cynarine in dried Echinacea angustifolia roots were extracted using pure ethanol (100%) at 25, 50 and 75°C for 30, 60 and 90 min with solvent to feed ratios of 20:1 and 10:1. Echinacoside and cynarine yields were significantly affected (p ≤ 0.05) by all three variables and increased with increasing temperature and time. Higher solvent to feed ratio generally resulted in higher yields. The highest echinacoside and cynarine yields obtained were 0.82% and 1.10%, respectively.; Alkylamides in fresh and dried E. angustifolia roots were extracted using supercritical carbon dioxide at 45, 60°C and 34, 55 MPa. Alkylamide yield of fresh roots increased with increasing temperature but decreased with increasing pressure while those from ground air-dried roots increased with higher temperature and pressure. The latter yielded the highest alkylamides as compared with those from fresh or unground dried roots. The use of freeze-dried roots did not give better extraction results as compared to air-dried roots for echinacoside, cynarine and alkylamides. |
