Abstract: The membrane separation conditions for dioscin from Dioscorea nipponica Makino were optimized by response surface methodology.The index component transfer rate as evaluation index,according to experiment of the single factor,three levels of membrane temperature ( ℃),membrane concentration (g/L) and membrane pressure (MPa) were selected.According to the Box-Behnken experimental design,Expert-Design software was used to analysis the date and get the optimal membrane separation condition.Results showed that the membrane separation condition:membrane temperature of 30 ℃,transmembrane concentration of 2 g/L,transmembrane pressure of 0.8 MPa,under these conditions,an average of transfer index component was 44.88%.Optimization of inorganic ceramic membrane separation of dioscin by response surface methodology,which can overcome the disadvantages of traditional water extraction and alcohol precipitation process leads to the loss of active ingredients,serious disadvantages of alcohol in large quantity and long production cycle.The developed method was practical and can be used for separation of dioscin.

Key words: Dioscorea nipponica, dioscin, response surface methodology, inorganic ceramic membrane