Objective: To optimize the processing technology of stir-baked Leonuri Fructus with central composite design-response surface methodology

and provide the basis for its normalized production. Method: Stir-baking processing technology was optimized by taking processing temperature

processing time and stir-baking machine speed as independent variables

contents of total alkaloids

stachydrine hydrochloride

water soluble extract and alcohol soluble extract as evaluation indexes

each level of independent variables were fitted by multiple regression fitting.Response surface methodology was used to select optimum processing technology.UV was adopted to determine the content of total alkaloids in stir-baked Leonuri Fructus at 520 nm.HPLC-ELSD was employed to determine the content of stachydrine hydrochloride with a mobile phase of acetonitrile-water (60:40)

the flow rate of 0.5 mL·min-1 and the drift tube temperature at 70℃. Result: Complex correlation coefficient of trinomial fitting was high.Optimum processing technology parameters were as follows:processing temperature at 219℃

processing time of 2 min

stir-baking machine speed of 14 r·min-1.Contents of total alkaloids

stachydrine hydrochloride

water soluble extract and alcohol soluble extract were 9.82

2.50

86.16

193.28 mg·g-1. Conclusion: Central composite design-response surface methodology can be used to optimize processing technology of stir-baked Leonuri Fructus

and it is simple with good prediction

which is suitable for standardized production of stir-baked Leonuri Fructus.