Optimization of Pressurized Microwave-assisted Extraction Technology of Capsaicin by Central Composite Design-response Surface Methodology

OBJECTIVE To optimize extraction technology of capsaicin by pressurized microwave-assisted extraction. METHODS Using extraction rate as dependent variables, using particle size, ratio of liquid to solid, extraction time, extraction temperature as independent variables, central composite design-response surface methodology were used to optimize the extracting process conditions. Through variance analysis and linear and binomial regression equation model fitting, the prediction analysis was carried out. RESULTS The optimum extraction conditions were as follows:particle size was 90 mesh, ratio of liquid to solid(mL:g) was 43:1, microwave temperature was 85℃, microwave time was 18 min, microwave power was 550 W, solvent was 75% ethanol. Under these conditions, the yield of capsaicin could reach 7.59 mg·g^-1(RSD was 2.52%, n=3), which was close to the model predictions. CONCLUSION Compared with traditional solvent reflux method, this method is simple and has higher extraction rate.