Optimization of microwave- assisted extraction for Konjac alkaloids by response surface methodology

The microwave- assisted extraction,infrared spectrum qualitative analysis and the acid dye colorimetry for quantitative analysis were carried out on the alkaloids from Konjac. Based on the single- factor( ethanol concentration,solid- liquid ratio,microwave time and temperature) tests,taken the solid- liquid ratio,extract temperature and extract time as independent variables and the content of the alkaloids from Konjac as dependent variable,the extract parameters of the alkaloids from Konjac were optimized by response surface methodology.The results showed that the optimized extract parameters were 95% ethanol as extraction solvent,solid- liquid ratio was1∶ 20.4( g / m L),extract time was 8 min,extract temperature was 60 ℃. Under the optimized extract conditions,the extraction rate of alkaloid reached 0.216%.