Optimization of Extraction Process for Total Flavonoids from Buckwheat Paste by Response Surface Analysis

In the study,response surface methodology is used to optimize the extraction of total flavonoids from buckwheat paste. The effects of four variables including ethanol concentration, extraction temperature, extraction time, material-to-liquid ratio and extraction power on the extraction rate of total flavonoids from buckwheat paste are investigated. The optimal extraction conditions are determined as follow:ethanol concentration 69%,material-to-liquid ratio 1∶16, extraction temperature 67 ℃ and extraction time 60 min. Under the conditions,the predicted and experimental extraction rates of total flavonoids are 1.596 5% and 1.527 6%,respectively. The deviation between the predicted and experimental extraction rates of total flavonoids is small,showing that this method applies to optimization of extraction process for total flavonoids from buckwheat paste is feasible.