Development of an SVR model for microwave-assisted aqueous two-phase extraction of isoflavonoids from Radix Puerariae

Abstract

In this study, simultaneous extraction and purification of isoflavonoids from Radix Puerariae was carried out by the microwave-assisted aqueous two-phase extraction technique (MAATPE). An ethanol/K2HPO4 system was used to form an aqueous two-phase system. The critical factors, namely, the concentrations of K2HPO4 and ethanol, solid–liquid ratio, extraction temperature, extraction time, and microwave power were investigated. Subsequently, the least squares support vector regression (LS-SVR) as a machine learning method was used to establish the model and predict extraction yield. The final conditions were concluded as follows: ethanol concentration 29.5% (w/w) and K2HPO4 concentration 24.9% (w/w), extraction temperature 79 °C, extraction time 8 min, and microwave irradiation power 600 W. Under the optimal condition, the extraction yield of total isoflavonoids reached 13.39%, which was similar to the predicted value of 13.48%. The recovery of isoflavonoids was 94.6%, and the yield of puerarin was 49.5 mg/g.