Optimization of Microwave-assisted Extraction of Flavonoids of Green Tea Using Response Surface Analysis

Response surface methodology with three factors and three levels was used to optimize the microwave-assisted extraction of flavonoids of green tea,on the basis of a series of one-factor experiments,second linear regression equation was obtained with flavonoids yield as a response surface value by the Design-expert software,the optimum extraction conditions of flavonoids of green tea were determined as follows: 600 W of extraction power,3.5 min of extraction time,and 50 ∶ 1(mL/g) of liquid-to-solid ratio,and twice of extraction times,the extraction efficiency of flavonoids was up to 2.605 mg/g under the optimized conditions.Confirmative test indicated that the established model had good prediction ability.