Optimization of extraction process of limonin from the Zhi Que' endocarp by central composite design-response surface methodology

The surfactant sodium cumenesulfonate was used as the hydrotropic agent in place of organic solvent;the limonin in the endocarp of Zhi Que was extracted;three factors as the hydrotropic agent concentration, the hydrotropic agent dosage and the soak time were evaluated for the impact on the yield of the limonin in the endocarp of Zhi Que via single factor experiment;central composite design-response surface method was used to optimize the extraction process of limonin. The results showed that:the quadratic terms of the dosage, concentration and soak time of the hydrotropic agent sodium cumenesulfonate had significant effect on the yield of the limonin (p<0.0001). When the optimum technology parameter was as follows:The dosage of sodium cumenesulfonate solution 27.7 mL/g, the concentration of sodium cumenesulfonate solution 2.3 mol/L, and the soak time 7.0 h, the limonin extracted from the endocarp of Zhi Que (4.32 mg/g) was close to the theoretical value on response surface 4.37 mg/g, indicating that the usage of central composite design-response surface method was feasible to optimize the extraction process of limonin.