| Supercritical CO2 extraction technology on azadirachtin A from neem kernels was optimized by Box -Behnken center composite design. Taking extraction temperature, extraction pressure and entrainer dose as response variables, and azadirachin A (mass fraction) as response values, the extraction process was optimized by the method of response surface methodology and based on single-factor experiments and Box-Behnken central composite experimental design. The quadratic regression model for the extraction azadirachin A was as follows: Y=0.3+0.067A+0.02B+0.043C+0.016AB -0.006AC +0.03BC -0.008A2 +0.014B2 -0.03C2. The R2 was 0.9705, and P <0.01, reaching the level of verysignificance, demonstrating that the equation being well regression. The results showed that the optimal process conditions of supercritical CO2 extraction extracting azadirachtin A by response surface methodology were as follows: extraction temperature 40益, extraction pressure 28.36 MPa and entrainer dose 2.79%; Under these conditions, the practical value of azadirachtin A was 0.40%, which agreed well with the predicted value of 0.42%. So extraction model of azadirachtin A established by Box- Behnken method precisely predicted the experiment results. |
