Process Optimization by Response Surface Methodology for the Extraction of Water Soluble Flavonoids from Coreopsis tinctoria Flowers

Response surface methodology(RSM) was applied to optimize the extractions of water soluble flavonoids from Coreopsis tinctoria flowers using water as the extraction solvent.The effects of extraction temperature,material/liquid ratio,particle size and extraction time on the extraction efficiency of water soluble flavonoids were investigated.The optimal extraction conditions were extraction temperature of 90 ℃,material/liquid ratio of 1:90,extraction time of 60 min and raw material particle size of 40 mesh.The actual extraction rate of flavonoids from Coreopsis tinctoria under the optimal extraction conditions was 24.85%,which was close to the predicted value.