Optimization of extraction process of total phenolic acids from Syringa oblate Lindl. leaves by response surface methodology

Total phenolic acids extraction from Syringa oblate Lindl. leaves was performed using the ethanol reflux extraction. Response surface methodology (RSM) , based on a three level, four variable Box-Behnken design ( BBD) , was employed to obtain the best possible combination of ethanol concentration, extraction temperature, extraction time, and water to the raw material ratio for maximum total phenolic acids extraction.The optimum extraction conditions were as follows:ethanol concentration of 44%, extraction time of 96 min, extraction temperature of 90℃, and the ratio of water to raw material of 25.2 ∶1 (m L/g) , extraction times of 2.Under these conditions, the experimental yield was (1.642±0.23) mg/g. The extraction process obtained by response surface methodology was stable and reasonable, accurate and reliable. It was a feasible method to extract the total phenolic acids from Syringa oblate Lindl. Leaves.