[Optimization of SFE-CO2 Extraction for Ursolic Acid from Punica granatum Peel by Plackett-Burman and Central Composite Design].

Objective: The optimum extraction of ursolic acid from Punica granatum peel by SFE-CO2 was investigated.

Methods: Based on the design of Plackett-Burman(PB), significant factors influencing the yield of ursolic acid in the operation process were filtered, with the extraction rate of ursolic acid as the index. The results obtained by steepest ascent method approximated the maximum area of ursolic acid yield.