Optimization Extraction Conditions of Some Flavonoids from Elsholtzia ciliata Leaves by Response Surface Method

In this study, the extraction conditions of several flavonoid compounds from Elsholtzia ciliata leaves were optimized by the response surface method (RSM). The experiment was arranged according to the Box - Behnken design with 15 experiments and was built based on an optimized process for the extraction of ethyl gallate (Y1), rutin (Y2), apigenin (Y3), and quercetin (Y4) with 3 factors of extraction temperature (X1), extraction time (X2) and pressure (X3). The conditions for optimizing the extraction process to obtain the highest content of some flavonoid compounds were at
C, 54 minutes, and 100 bar pressure. The experimental values at the optimal parameters of ethyl gallate, rutin, apigenin, and quercetin are 97.65 ± 0.32 mg/100g, 35.50 ± 0.25 mg/100g, 17.62 ± 0.15 mg/100g, and 27.66 ± 0.20 mg/100g, respectively.