Microwave Extraction Process for Multi-Index Components of Buddleja lindleyana Fortune Optimized Based on AHP-CRITIC Weighting Combined with Response Surface Methodology

The effects of particle size, microwave power, liquid-solid ratio, extraction solvent, extraction time, and extraction times on the microwave extraction of Buddleja lindleyana Fortune, using the yields of linarin, acteoside, acacetin and the paste as evaluation indexes, were investigated through single-factor experiments. The analytic hierarchy process (AHP) and criteria importance through inter-criteria correlation (CRITIC) method were combined to conduct an objective and subjective weighting of each evaluation index, and the Box-Behnken response surface methodology (RSM) was applied to design a total of 29 experiments with four factors at three levels. With the comprehensive score serving as the response value, the microwave extraction process for Buddleja lindleyana Fortune was optimized and the in vitro antioxidant activity of the extract was tested. With a fixed particle size of 120-mesh (120 μm) and two extraction cycles, the optimal extraction conditions were obtained as follows: A microwave power of 325 W, a liquid-solid ratio of 65 mL/g, an ethanol volume fraction of 66%, and an extraction time of 8 min. With these parameters set, the yield of linarin, acteoside and acacetin was determined to be 5.417%, 0.728% and 0.175%, respectively, and the paste yield was determined to be 25.769%, with a comprehensive score of 99.19 (RSD=0.45%). The optimized extraction process is simple, stable and efficient, and the obtained extract exhibited antioxidant activity.